added rudel (obby and other colab framework for emacs)

18 files changed, 6239 insertions, 0 deletions

diff --git a/emacs.d/lisp/rudel/obby/.svn/all-wcprops b/emacs.d/lisp/rudel/obby/.svn/all-wcprops
new file mode 100644
index 0000000..1794a33
--- /dev/null
+++ b/emacs.d/lisp/rudel/obby/.svn/all-wcprops
@@ -0,0 +1,53 @@
+K 25
+svn:wc:ra_dav:version-url
+V 38
+/svnroot/rudel/!svn/ver/468/trunk/obby
+END
+rudel-obby-client.el
+K 25
+svn:wc:ra_dav:version-url
+V 59
+/svnroot/rudel/!svn/ver/397/trunk/obby/rudel-obby-client.el
+END
+rudel-obby-state.el
+K 25
+svn:wc:ra_dav:version-url
+V 58
+/svnroot/rudel/!svn/ver/330/trunk/obby/rudel-obby-state.el
+END
+Project.ede
+K 25
+svn:wc:ra_dav:version-url
+V 50
+/svnroot/rudel/!svn/ver/215/trunk/obby/Project.ede
+END
+rudel-obby.el
+K 25
+svn:wc:ra_dav:version-url
+V 52
+/svnroot/rudel/!svn/ver/397/trunk/obby/rudel-obby.el
+END
+rudel-obby-debug.el
+K 25
+svn:wc:ra_dav:version-url
+V 58
+/svnroot/rudel/!svn/ver/318/trunk/obby/rudel-obby-debug.el
+END
+rudel-obby-server.el
+K 25
+svn:wc:ra_dav:version-url
+V 59
+/svnroot/rudel/!svn/ver/356/trunk/obby/rudel-obby-server.el
+END
+rudel-obby-errors.el
+K 25
+svn:wc:ra_dav:version-url
+V 59
+/svnroot/rudel/!svn/ver/319/trunk/obby/rudel-obby-errors.el
+END
+rudel-obby-util.el
+K 25
+svn:wc:ra_dav:version-url
+V 57
+/svnroot/rudel/!svn/ver/468/trunk/obby/rudel-obby-util.el
+END
diff --git a/emacs.d/lisp/rudel/obby/.svn/entries b/emacs.d/lisp/rudel/obby/.svn/entries
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index 0000000..2d21fc4
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+++ b/emacs.d/lisp/rudel/obby/.svn/entries
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+10
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+dir
+545
+https://rudel.svn.sourceforge.net/svnroot/rudel/trunk/obby
+https://rudel.svn.sourceforge.net/svnroot/rudel
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+2009-10-16T01:48:03.160288Z
+468
+scymtym
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+694b31df-dcbb-44e8-af88-74c7ea918228
+
+rudel-obby-client.el
+file
+
+
+
+
+2009-11-18T14:01:44.000000Z
+9cb0ae63b9f86199be36f208feb51b26
+2009-10-10T00:39:13.745463Z
+397
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+
+rudel-obby-state.el
+file
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+2009-11-18T14:01:44.000000Z
+f7a018739f96fe975da0ab4cc112e7e4
+2009-10-03T01:58:59.186010Z
+330
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+4955
+
+Project.ede
+file
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+2009-11-18T14:01:44.000000Z
+a99a4bf5a1243e8bd25e87d74b02db1d
+2009-10-03T00:45:44.545055Z
+215
+scymtym
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+388
+
+rudel-obby.el
+file
+
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+
+2009-11-18T14:01:44.000000Z
+af5ba069b2183fac68261ba2d34f199d
+2009-10-10T00:39:13.745463Z
+397
+scymtym
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+15453
+
+rudel-obby-debug.el
+file
+
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+
+2009-11-18T14:01:44.000000Z
+915461ef0b7ccb7dbad60a69aa973389
+2009-10-03T01:56:22.854481Z
+318
+scymtym
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+3300
+
+rudel-obby-server.el
+file
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+2009-11-18T14:01:44.000000Z
+cd9ab22e9a8d09b558693edfc7b5505a
+2009-10-03T02:08:53.322972Z
+356
+scymtym
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+24935
+
+rudel-obby-errors.el
+file
+
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+
+2009-11-18T14:01:44.000000Z
+72c6c1dfe7ec7b8a95d5808d439088dd
+2009-10-03T01:56:39.182216Z
+319
+scymtym
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+1839
+
+rudel-obby-util.el
+file
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+2009-11-18T14:01:44.000000Z
+991ece971eaeba3b86359fc05a410b9d
+2009-10-16T01:48:03.160288Z
+468
+scymtym
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diff --git a/emacs.d/lisp/rudel/obby/.svn/text-base/Project.ede.svn-base b/emacs.d/lisp/rudel/obby/.svn/text-base/Project.ede.svn-base
new file mode 100644
index 0000000..53d2422
--- /dev/null
+++ b/emacs.d/lisp/rudel/obby/.svn/text-base/Project.ede.svn-base
@@ -0,0 +1,14 @@
+;; Object rudel/obby
+;; EDE project file.
+(ede-proj-project "rudel/obby"
+  :name "obby"
+  :file "Project.ede"
+  :targets (list 
+   (ede-proj-target-elisp "obby"
+    :name "obby"
+    :path ""
+    :source '("rudel-obby.el" "rudel-obby-util.el" "rudel-obby-client.el" "rudel-obby-server.el" "rudel-obby-errors.el" "rudel-obby-state.el")
+    :aux-packages '("rudel" "jupiter")
+    )
+   )
+  )
diff --git a/emacs.d/lisp/rudel/obby/.svn/text-base/rudel-obby-client.el.svn-base b/emacs.d/lisp/rudel/obby/.svn/text-base/rudel-obby-client.el.svn-base
new file mode 100644
index 0000000..5c192db
--- /dev/null
+++ b/emacs.d/lisp/rudel/obby/.svn/text-base/rudel-obby-client.el.svn-base
@@ -0,0 +1,973 @@
+;;; rudel-obby-client.el --- Client functions of the Rudel obby backend
+;;
+;; Copyright (C) 2008, 2009 Jan Moringen
+;;
+;; Author: Jan Moringen <scymtym@users.sourceforge.net>
+;; Keywords: Rudel, obby, backend, client
+;; X-RCS: $Id:$
+;;
+;; This file is part of Rudel.
+;;
+;; Rudel is free software: you can redistribute it and/or modify it
+;; under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+;;
+;; Rudel is distributed in the hope that it will be useful, but
+;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+;; General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with Rudel. If not, see <http://www.gnu.org/licenses>.
+
+
+;;; Commentary:
+;;
+;; This file contains the client part of the obby backend.
+
+
+;;; History:
+;;
+;; 0.2 - State machine.
+;;
+;; 0.1 - Initial revision.
+
+
+;;; Code:
+;;
+
+(require 'eieio)
+
+(require 'jupiter)
+
+(require 'rudel-state-machine)
+(require 'rudel-operations)
+(require 'rudel-chat)
+
+(require 'rudel-obby-errors)
+(require 'rudel-obby-util)
+(require 'rudel-obby-state)
+
+
+;;; Class rudel-obby-client-state-new
+;;
+
+(defclass rudel-obby-client-state-new
+  (rudel-obby-client-connection-state)
+  ()
+  "Start state of newly established connections.")
+
+(defmethod rudel-obby/obby_welcome
+  ((this rudel-obby-client-state-new) version)
+  "Handle obby 'welcome' message."
+  ;; Examine announced protocol version.
+  (with-parsed-arguments ((version number))
+    (message "Received Obby welcome message (version %d)" version))
+  ;; Start encryption handshake
+  'encryption-negotiate)
+
+
+;;; Class rudel-obby-client-state-encryption-negotiate
+;;
+
+(defclass rudel-obby-client-state-encryption-negotiate
+  (rudel-obby-client-connection-state)
+  ()
+  "Start state of the encryption handshake.")
+
+(defmethod rudel-obby/net6_encryption
+  ((this rudel-obby-client-state-encryption-negotiate) value)
+  "Handle net6 'encryption' message."
+  (rudel-send this "net6_encryption_ok")
+  'encryption-start)
+
+
+;;; Class rudel-obby-client-connection-encryption-start
+;;
+
+(defclass rudel-obby-client-state-encryption-start
+  (rudel-obby-client-connection-state)
+  ()
+  "Second state of the encryption handshake.")
+
+(defmethod rudel-obby/net6_encryption_begin
+  ((this rudel-obby-client-state-encryption-start))
+  "Handle net6 'encryption_begin' message."
+  ;; Start TLS encryption for the connection.
+  (with-slots (connection) this
+    (with-slots (socket) connection
+      (when (rudel-process-object socket :supports-tls)
+	(rudel-tls-start-tls socket)
+	(sit-for 1))))
+
+  ;; The connection is now established
+  'joining)
+
+(defmethod rudel-obby/net6_encryption_failed
+  ((this rudel-obby-client-state-encryption-start))
+  "Handle net6 'encryption_failed' message."
+  ;; The connection is now established; without encryption though
+  'joining)
+
+
+;;; Class rudel-obby-client-state-joining
+;;
+
+(defclass rudel-obby-client-state-joining
+  (rudel-obby-client-connection-state)
+  ()
+  "First state after the connection has been properly set up.")
+
+(defmethod rudel-enter ((this rudel-obby-client-state-joining))
+  "When entering this state, send a login request."
+  ;; Send login request with username and color. This can easily fail
+  ;; (resulting in response 'net6_login_failed') if the username or
+  ;; color is already taken.
+  (with-slots (info) (oref this connection)
+    (let ((username        (plist-get info :username))
+	  (color           (plist-get info :color))
+	  (global-password (plist-get info :global-password))
+	  (user-password   (plist-get info :user-password)))
+      (apply #'rudel-send
+	     this
+	     "net6_client_login"
+	     username (rudel-obby-format-color color)
+	     (append (when global-password
+		       (list global-password))
+		     (when (and global-password user-password)
+		       (list user-password))))))
+  nil)
+
+(defmethod rudel-obby/obby_sync_init
+  ((this rudel-obby-client-state-joining) count)
+  "Handle obby 'sync_init' message."
+  ;; Switch to 'synching' state, passing the number of synchronization
+  ;; items.
+  (with-parsed-arguments ((count number))
+    (list 'session-synching count)))
+
+(defmethod rudel-obby/net6_login_failed
+  ((this rudel-obby-client-state-joining) reason)
+  "Handle net6 'login_failed' message."
+  (with-parsed-arguments ((reason number))
+    (with-slots (connection) this
+      (let ((error-data
+	     (cond
+	      ;; Invalid username
+	      ((= reason rudel-obby-error-username-invalid)
+	       (cons 'rudel-obby-username-invalid nil))
+	      ;; Username in use
+	      ((= reason rudel-obby-error-username-in-use)
+	       (cons 'rudel-obby-username-in-use nil))
+	      ;; Color in use
+	      ((= reason rudel-obby-error-color-in-use)
+	       (cons 'rudel-obby-color-in-use nil))
+	      ;; Wrong global password
+	      ((= reason rudel-obby-error-wrong-global-password)
+	       (cons 'rudel-obby-wrong-global-password nil))
+	      ;; Wrong user password
+	      ((= reason rudel-obby-error-wrong-user-password)
+	       (cons 'rudel-obby-wrong-user-password nil))
+	      ;; Otherwise, signal a generic join error
+	      (t (cons 'rudel-join-error nil)))))
+
+	;; Switch to 'join-failed' state, pass the error data.
+	(list 'join-failed error-data))))
+  )
+
+
+;;; Class rudel-obby-client-state-join-failed
+;;
+
+(defclass rudel-obby-client-state-join-failed
+  (rudel-obby-client-connection-state)
+  ((error-symbol :initarg :error-symbol
+		 :type    symbol
+		 :documentation
+		 "Error symbol describing the reason for the
+login failure.")
+   (error-data   :initarg :error-data
+		 :type    list
+		 :documentation
+		 "Additional error data describing the login
+failure."))
+  "State for failed login attempts.")
+
+(defmethod rudel-enter ((this rudel-obby-client-state-join-failed)
+			error)
+  "When the state is entered, store the error data passed in ERROR."
+  (with-slots (error-symbol error-data) this
+    (setq error-symbol (car error)
+	  error-data   (cdr error)))
+  nil)
+
+
+;;; Class rudel-obby-client-state idle
+;;
+
+(defclass rudel-obby-client-state-idle
+  (rudel-obby-client-connection-state
+   rudel-obby-document-handler)
+  ()
+  "Default state of the connection.")
+
+(defmethod rudel-obby/net6_client_join
+  ((this rudel-obby-client-state-idle)
+   client-id name encryption user-id color)
+  "Handle net6 'client_join' message."
+  (with-parsed-arguments ((client-id number)
+			  (user-id   number)
+			  (color     color))
+    (with-slots (connection) this
+      (with-slots (session) connection
+	(let ((user (rudel-find-user session user-id
+				     #'eq #'rudel-id)))
+	  (if user
+	      ;; If we have such a user object, update its state.
+	      (with-slots ((client-id1  client-id)
+			   (color1      color)
+			   connected
+			   (encryption1 encryption)) user
+		(setq client-id1  client-id
+		      color1      color
+		      connected   t
+		      encryption1 (string= encryption "1"))
+
+		;; Run the change hook of the user object.
+		(object-run-hook-with-args user 'change-hook))
+	    ;; Otherwise, create a new user object.
+	    (let ((user (rudel-obby-user
+			 name
+			 :client-id  client-id
+			 :user-id    user-id
+			 :connected  t
+			 :encryption (string= encryption "1")
+			 :color      color)))
+	      (rudel-add-user session user))))))
+    (message "Client joined: %s %s" name color))
+  nil)
+
+(defmethod rudel-obby/net6_client_part
+  ((this rudel-obby-client-state-idle) client-id)
+  "Handle net6 'client_part' message."
+  ;; Find the user object, associated to the client id. Remove the
+  ;; client id and change the user's state to disconnected.
+  (with-parsed-arguments ((client-id number))
+    (with-slots (connection) this
+      (with-slots (session) connection
+	(let ((user (rudel-find-user session client-id
+				     #'eql #'rudel-client-id)))
+	  (if user
+	      (with-slots (client-id connected) user
+		;; Set slot values.
+		(setq client-id nil
+		      connected nil)
+
+		;; Run the change hook of the user object.
+		(object-run-hook-with-args user 'change-hook))
+	    (display-warning
+	     '(rudel obby)
+	     (format "Cannot find user for client id: %d"
+		     client-id)
+	     :warning))))))
+  nil)
+
+(defmethod rudel-obby/obby_user_colour
+  ((this rudel-obby-client-state-idle) user-id color)
+  "Handle obby 'user_colour' message."
+  (with-parsed-arguments ((user-id number)
+			  (color   color))
+    ;; Find user object and set color.
+    (with-slots (connection) this
+      (with-slots (session) connection
+	(let ((user (rudel-find-user session user-id
+				     #'= #'rudel-id)))
+	  (with-slots ((name :object-name) (color1 :color)) user
+	    ;; Set color in user object.
+	    (setq color1 color)
+
+	    ;; Run the change hook of the user object.
+	    (object-run-hook-with-args user 'change-hook)
+
+	    ;; Update overlays.
+	    (rudel-overlay-set-face-attributes
+	     (rudel-overlay-make-face-symbol 'author name)
+	     color1))))))
+  nil)
+
+(defmethod rudel-obby/obby_document_create
+  ((this rudel-obby-client-state-idle)
+   owner-id doc-id name suffix encoding)
+  "Handle obby 'document_create' message."
+  (with-parsed-arguments ((owner-id number)
+			  (doc-id   number)
+			  (suffix   number)
+			  (encoding coding-system))
+    (with-slots (connection) this
+      (with-slots (session) connection
+	(let ((owner (rudel-find-user session owner-id
+				      #'= #'rudel-id)))
+	  (rudel-add-document session (rudel-obby-document
+				       name
+				       :subscribed (list owner)
+				       :id         doc-id
+				       :owner-id   owner-id
+				       :suffix     suffix))))
+      (message "New document: %s" name)))
+  nil)
+
+(defmethod rudel-obby/obby_document_remove
+  ((this rudel-obby-client-state-idle) doc-id)
+  "Handle obby 'document_remove' message."
+  (with-parsed-arguments ((doc-id document-id))
+    (with-slots (connection) this
+      (with-slots (session) connection
+	(let ((document (rudel-find-document
+			 session doc-id
+			 #'equal #'rudel-both-ids)))
+	  (if document
+	      (progn
+		(rudel-remove-document session document)
+		(with-slots ((name :object-name)) document
+		  (message "Document removed: %s" name)))
+	    (display-warning
+	     '(rudel obby)
+	     (format "Document not found: %s" doc-id)
+	     :warning))))))
+  nil)
+
+(defmethod rudel-obby/obby_document/rename
+  ((this rudel-obby-client-state-idle)
+   document user new-name new-suffix)
+  "Handle obby 'rename' submessage of the 'obby_document' message."
+  (with-parsed-arguments ((new-suffix number))
+    (with-slots ((name :object-name) suffix) document
+      (setq name   new-name
+	    suffix new-suffix)))
+  nil)
+
+(defmethod rudel-obby/obby_document/subscribe
+  ((this rudel-obby-client-state-idle)
+   document user-id)
+  "Handle 'subscribe' submessage of obby 'document' message."
+  (with-parsed-arguments ((user-id number))
+    (with-slots (connection) this
+      (with-slots (session) connection
+	(let ((user (rudel-find-user session user-id
+				     #'= #'rudel-id)))
+	  (rudel-add-user document user)))))
+  nil)
+
+(defmethod rudel-obby/obby_document/unsubscribe
+  ((this rudel-obby-client-state-idle)
+   document user-id)
+  "Handle 'unsubscribe' submessage of obby 'document' message."
+  (with-parsed-arguments ((user-id number))
+    (with-slots (connection) this
+      (with-slots (session) connection
+	(let ((user (rudel-find-user session user-id
+				     #'= #'rudel-id)))
+	  (rudel-remove-user document user)))))
+  nil)
+
+(defmethod rudel-obby/obby_document/record
+  ((this rudel-obby-client-state-idle)
+   document user-id local-revision remote-revision
+   action &rest arguments)
+  "Handle 'record' submessage of obby 'document' message."
+  (with-parsed-arguments ((user-id         number)
+			  (local-revision  number)
+			  (remote-revision number))
+    ;; Locate the user.
+    (let ((user (with-slots (connection) this
+		  (with-slots (session) connection
+		    (rudel-find-user session user-id
+				     #'= #'rudel-id)))))
+      (if user
+	  (condition-case error
+	      ;; Try to dispatch
+	      (rudel-dispatch
+	       this "rudel-obby/obby_document/record/" action
+	       (append (list document user local-revision remote-revision)
+		       arguments))
+	    ;; Warn if we failed to locate or execute the
+	    ;; method. Return nil in this case, so we remain in the
+	    ;; current state.
+	    (rudel-dispatch-error
+	     (progn
+	       (display-warning
+		'(rudel obby)
+		(format "%s: no method (%s: %s): `%s:%s'; arguments: %s"
+			(object-print this) (car error) (cdr error)
+			"rudel-obby/obby_document/record/" action arguments)
+		:debug)
+		nil)))
+	;; If we did not find the user, warn.
+	(progn
+	  (display-warning
+	   '(rudel obby)
+	   (format "User not found: %d" user-id)
+	   :warning)
+	  nil))))
+  )
+
+(defmethod rudel-obby/obby_document/record/ins
+  ((this rudel-obby-client-state-idle)
+   document user local-revision remote-revision
+   position data)
+  "Handle 'ins' submessage of 'record' submessage of obby 'document' message."
+  (with-parsed-arguments ((position number))
+    (let ((operation (jupiter-insert
+		      (format "insert-%d-%d"
+			      remote-revision local-revision)
+		      :from position
+		      :data data)))
+      (with-slots (connection) this
+	(rudel-remote-operation connection
+				document user
+				remote-revision local-revision
+				operation))))
+  nil)
+
+(defmethod rudel-obby/obby_document/record/del
+  ((this rudel-obby-client-state-idle)
+   document user local-revision remote-revision
+   position length)
+  "Handle 'del' submessage of 'record' submessage of obby 'document' message."
+  (with-parsed-arguments ((position number)
+			  (length   number))
+    (let ((operation (jupiter-delete
+		      (format "delete-%d-%d"
+			      remote-revision local-revision)
+		      :from position
+		      :to   (+ position length))))
+      (with-slots (connection) this
+	(rudel-remote-operation connection
+				document user
+				remote-revision local-revision
+				operation))))
+  nil)
+
+(defmethod rudel-obby/obby_document/record/split
+  ((this rudel-obby-client-state-idle)
+   document user local-revision remote-revision
+   &rest operations)
+  "Handle 'split' submessage of 'record' submessage of obby 'document' message."
+  (let ((operation (rudel-message->operation
+		    (cons "split" operations)
+		    local-revision remote-revision)))
+    (with-slots (connection) this
+      (rudel-remote-operation connection
+			      document user
+			      remote-revision local-revision
+			      operation)))
+  nil)
+
+(defmethod rudel-obby/obby_document/record/noop
+  ((this rudel-obby-client-state-idle)
+   document user local-revision remote-revision)
+  "Handle 'noop' submessage of 'record' submessage of obby 'document' message."
+  (let ((operation (jupiter-nop
+		    (format "nop-%d-%d"
+			    remote-revision local-revision))))
+    (with-slots (connection) this
+      (rudel-remote-operation connection
+			      document user
+			      remote-revision local-revision
+			      operation)))
+  nil)
+
+(defmethod rudel-obby/obby_message ((this rudel-obby-client-state-idle)
+				    sender text)
+  "Handle obby 'message' message"
+  (with-parsed-arguments ((sender number))
+    (with-slots (session) (oref this :connection)
+      (let ((sender (rudel-find-user session sender #'eq #'rudel-id)))
+	(rudel-chat-dispatch-message sender text))))
+  nil)
+
+
+;;; Class rudel-obby-client-state-session-synching
+;;
+
+(defclass rudel-obby-client-state-session-synching
+  (rudel-obby-client-connection-state)
+  ((all-items       :initarg  :all-items
+		    :type     (integer 0)
+		    :documentation
+		    "Total number of synchronization items expected
+		    to receive from the server.")
+   (remaining-items :initarg  :remaining-items
+		    :type     (integer 0)
+		    :documentation
+		    "Number of synchronization items not yet
+		    received from the server.")
+   (have-self       :initarg  :have-self
+		    :type     boolean
+		    :documentation
+		    "Flag that remembers, whether the session has
+		    a 'self' user object."))
+  "State used for synching session data.")
+
+(defmethod rudel-enter ((this rudel-obby-client-state-session-synching)
+			num-items)
+  "When entering state, store number of expected items."
+  (with-slots (all-items remaining-items have-self) this
+    (setq all-items       num-items
+	  remaining-items num-items
+	  have-self       nil))
+  nil)
+
+(defmethod rudel-obby/net6_client_join
+  ((this rudel-obby-client-state-session-synching)
+   client-id name encryption user-id color)
+  "Handle net6 'client_join' message."
+  (with-parsed-arguments ((client-id number)
+			  (user-id   number)
+			  (color     color))
+    (with-slots (connection remaining-items have-self) this
+      (with-slots (session) connection
+	;; Construct user object and add it to the session.
+	(let ((user (rudel-obby-user
+		     name
+		     :client-id  client-id
+		     :user-id    user-id
+		     :connected  t
+		     :encryption (string= encryption "1")
+		     :color      color)))
+	  (rudel-add-user session user)
+
+	  ;; The first user object describes the user of this client.
+	  (unless have-self
+	    (with-slots (self) session
+	      (setq self      user
+		    have-self t)))))
+
+      ;; Decrease number of not yet received synchronization items.
+      (decf remaining-items)))
+  nil)
+
+(defmethod rudel-obby/obby_sync_usertable_user
+  ((this rudel-obby-client-state-session-synching) user-id name color)
+  "Handle obby 'sync_usertable_user' message."
+  (with-parsed-arguments ((user-id number)
+			  (color   color))
+    (with-slots (connection remaining-items) this
+      (with-slots (session) connection
+	(rudel-add-user session (rudel-obby-user
+				 name
+				 :user-id    user-id
+				 :connected  nil
+				 :color      color)))
+
+      ;; Decrease number of not yet received synchronization items.
+      (decf remaining-items)))
+  nil)
+
+(defmethod rudel-obby/obby_sync_doclist_document
+  ((this rudel-obby-client-state-session-synching)
+   owner-id doc-id name suffix encoding &rest subscribed-user-ids)
+  "Handle obby 'sync_doclist_document' message."
+  (with-parsed-arguments ((doc-id   number)
+			  (owner-id number)
+			  (suffix   number)
+			  (encoding coding-system))
+    (with-slots (connection remaining-items) this
+      (with-slots (session) connection
+	;; Retrieve the subscribed users
+	(let ((subscribed-users
+	       (mapcar
+		(lambda (user-id)
+		  (with-parsed-arguments ((user-id number))
+		    (rudel-find-user session user-id
+				     #'= #'rudel-id)))
+		subscribed-user-ids)))
+
+	  ;; Make a new document with the list of subscribed users.
+	  (rudel-add-document session (rudel-obby-document
+				       name
+				       :subscribed subscribed-users
+				       :id         doc-id
+				       :owner-id   owner-id
+				       :suffix     suffix))))
+
+      ;; Decrease number of not yet received synchronization items.
+      (decf remaining-items)))
+  nil)
+
+(defmethod rudel-obby/obby_sync_final
+  ((this rudel-obby-client-state-session-synching))
+  "Handle obby 'sync_final' message."
+  'idle)
+
+(defmethod object-print ((this rudel-obby-client-state-session-synching)
+			 &rest strings)
+  "Append number of remaining items to string representation."
+  (with-slots (remaining-items) this
+    (call-next-method this (format " remaining: %d" remaining-items))))
+
+
+;;; Class rudel-obby-client-state-subscribing
+;;
+
+(defclass rudel-obby-client-state-subscribing
+  (rudel-obby-client-connection-state
+   rudel-obby-document-handler)
+  ((document :initarg :document
+	     :type    rudel-obby-document-child
+	     :documentation
+	     ""))
+  "")
+
+(defmethod rudel-enter ((this rudel-obby-client-state-subscribing)
+			user document)
+  "When entering this state, send a subscription request to the server."
+  (with-slots ((document1 :document)) this
+    (setq document1 document)
+
+    (with-slots ((doc-id :id) owner-id) document1
+      (with-slots (user-id) user
+	(rudel-send this "obby_document"
+		    (format "%x %x" owner-id doc-id)
+		    "subscribe"
+		    (format "%x" user-id)))))
+  nil)
+
+(defmethod rudel-obby/obby_document/sync_init
+  ((this rudel-obby-client-state-subscribing)
+   document num-bytes)
+  "Handle obby 'sync_init' message."
+  (with-parsed-arguments ((num-bytes number))
+    (with-slots (documents) this
+      (if (= num-bytes 0)
+	  'idle
+	(list 'document-synching document num-bytes))))
+  )
+
+
+;;; Class rudel-obby-client-state-document-synching
+;;
+
+(defclass rudel-obby-client-state-document-synching
+  (rudel-obby-client-connection-state
+   rudel-obby-document-handler)
+  ((document        :initarg  :document
+		    :type     rudel-obby-document-child
+		    :documentation
+		    "")
+   (all-bytes       :initarg  :all-bytes
+		    :type     (integer 0)
+		    :documentation
+		    "")
+   (remaining-bytes :initarg  :remaining-bytes
+		    :type     (integer 0)
+		    :documentation
+		    ""))
+  "")
+
+(defmethod rudel-enter ((this rudel-obby-client-state-document-synching)
+			document num-bytes)
+  ""
+  (with-slots ((document1 :document) all-bytes remaining-bytes) this
+    (setq document1       document
+	  all-bytes       num-bytes
+	  remaining-bytes num-bytes))
+  nil)
+
+(defmethod rudel-obby/obby_document/sync_chunk
+  ((this rudel-obby-client-state-document-synching)
+   document data user-id)
+  "Handle obby 'sync_chunk' message."
+  (with-parsed-arguments ((user-id number))
+    (with-slots (connection remaining-bytes) this
+      (with-slots (session) connection
+	(let* ((user      (unless (zerop user-id)
+			    (rudel-find-user session user-id
+					     #'= #'rudel-id)))
+	       (operation (rudel-insert-op "bulk-insert"
+					   :from nil
+					   :data data)))
+	  (rudel-remote-operation document user operation)))
+
+      ;; After all bytes are transferred, go back to idle state.
+      (decf remaining-bytes (string-bytes data))
+      (if (= remaining-bytes 0)
+	  'idle
+	nil)))
+  )
+
+(defmethod object-print ((this rudel-obby-client-state-document-synching)
+			 &rest strings)
+  "Append number of remaining items to string representation."
+  (with-slots (remaining-bytes) this
+    (call-next-method this (format " remaining: %d" remaining-bytes))))
+
+
+;;; Class rudel-obby-client-state-they-finalized
+;;
+
+(defclass rudel-obby-client-state-they-finalized
+  (rudel-obby-client-connection-state)
+  ()
+  "State used to indicate that the connection was closed by the peer.")
+
+
+;;; Client connection states.
+;;
+
+(defvar rudel-obby-client-connection-states
+  '((new                  . rudel-obby-client-state-new)
+    (encryption-negotiate . rudel-obby-client-state-encryption-negotiate)
+    (encryption-start     . rudel-obby-client-state-encryption-start)
+    (joining              . rudel-obby-client-state-joining)
+    (join-failed          . rudel-obby-client-state-join-failed)
+    (idle                 . rudel-obby-client-state-idle)
+    (session-synching     . rudel-obby-client-state-session-synching)
+    (subscribing          . rudel-obby-client-state-subscribing)
+    (document-synching    . rudel-obby-client-state-document-synching)
+    (they-finalized       . rudel-obby-client-state-they-finalized))
+  "Name symbols and classes of connection states.")
+
+
+;;; Class rudel-obby-connection
+;;
+
+(defclass rudel-obby-connection (rudel-obby-socket-owner
+				 rudel-connection
+				 rudel-state-machine)
+  ((info     :initarg :info
+	     :type    list
+	     :documentation
+	     "Stores connection information for later use.")
+   (contexts :initarg :contexts
+	     :type    hash-table
+	     :documentation
+	     "Contains jupiter context objects for all
+documents."))
+  "Class rudel-obby-connection ")
+
+(defmethod initialize-instance ((this rudel-obby-connection) &rest slots)
+  ;; Initialize slots of THIS
+  (when (next-method-p)
+    (call-next-method))
+
+  ;; Create a new hash-table object to hold jupiter contexts
+  ;; associated to documents.
+  (with-slots (contexts) this
+    (setq contexts (make-hash-table :test #'equal)))
+
+  ;; Register states.
+  (rudel-register-states this rudel-obby-client-connection-states)
+  )
+
+(defmethod rudel-register-state ((this rudel-obby-connection)
+				 symbol state)
+  "Register SYMBOL and STATE and set connection slot of STATE."
+  ;; Associate THIS connection to STATE.
+  (oset state :connection this)
+
+  ;; Register STATE.
+  (when (next-method-p)
+    (call-next-method))
+  )
+
+(defmethod rudel-disconnect ((this rudel-obby-connection))
+  ""
+  (when (next-method-p)
+    (call-next-method)))
+
+(defmethod rudel-close ((this rudel-obby-connection))
+  ""
+  ;; Move the state machine into an error state.
+  (rudel-switch this 'they-finalized)
+
+  ;; Terminate the session.
+  (with-slots (session) this
+    (rudel-end session)))
+
+(defmethod rudel-find-context ((this rudel-obby-connection) document)
+  "Return the jupiter context associated to DOCUMENT in THIS connection."
+  (with-slots (contexts) this
+    (gethash (oref document :id) contexts)))
+
+(defmethod rudel-add-context ((this rudel-obby-connection) document)
+  "Add a jupiter context for DOCUMENT to THIS connection."
+  (with-slots (contexts) this
+    (with-slots ((doc-name :object-name) (doc-id :id)) document
+      (puthash doc-id
+	       (jupiter-context (format "%s" doc-name))
+	       contexts)))
+  )
+
+(defmethod rudel-remove-context ((this rudel-obby-connection) document)
+  "Remove the jupiter context associated to DOCUMENT from THIS connection."
+  (with-slots (contexts) this
+    (remhash (oref document :id) contexts)))
+
+(defmethod rudel-message ((this rudel-obby-connection) message)
+  "Dispatch MESSAGE to the current state of THIS object.
+If the state has no suitable method, generate a warning, but do
+nothing else."
+  ;; Dispatch message to state.
+  (rudel-accept this message))
+
+(defmethod rudel-change-color- ((this rudel-obby-connection) color)
+  ""
+  (rudel-send this "obby_user_colour"
+	      (rudel-obby-format-color color)))
+
+(defmethod rudel-publish ((this rudel-obby-connection) document)
+  ""
+  ;; Create a new jupiter context for DOCUMENT.
+  (rudel-add-context this document)
+
+  ;; Announce the new document to the server.
+  (with-slots ((name :object-name) id buffer) document
+    (rudel-send this "obby_document_create"
+		(format "%x" id)
+		name
+		"UTF-8"
+		(with-current-buffer buffer
+		  (buffer-string))))
+  )
+
+(defmethod rudel-unpublish ((this rudel-obby-connection) document)
+  "Remove DOCUMENT from the obby session THIS is connected to."
+  ;; Request removal of DOCUMENT.
+  (with-slots ((doc-id :id) owner-id) document
+      (rudel-send this "obby_document_remove"
+		  (format "%x %x" owner-id doc-id)))
+
+  ;; Remove the jupiter context for DOCUMENT.
+  (rudel-remove-context this document)
+  )
+
+(defmethod rudel-subscribe-to ((this rudel-obby-connection) document)
+  ""
+  ;; Create a new jupiter context for DOCUMENT.
+  (rudel-add-context this document)
+
+  ;; Switch to subscribing state and wait until the state goes back to
+  ;; idle.
+  (with-slots (session) this
+    (with-slots (self) session
+      (rudel-switch this 'subscribing self document)))
+
+  (lexical-let ((reporter (make-progress-reporter "Subscribing " 0.0 1.0)))
+    (flet ((display-progress (state)
+	     (cond
+	      ;; Syncing document content, we can provide detailed progress.
+	      ((and (consp state)
+		    (eq (car state) 'document-synching))
+	       (with-slots (all-bytes remaining-bytes) (cdr state)
+		 (progress-reporter-force-update
+		  reporter
+		  (- 1.0 (/ (float remaining-bytes) (float all-bytes)))
+		  (format "Subscribing (%s) " (car state)))))
+
+	      ;; For other states, we just spin.
+	      ((consp state)
+	       (progress-reporter-force-update
+	        reporter 0.5
+	        (format "Subscribing (%s) " (car state))))
+
+	      ;; Done
+	      (t
+	       (progress-reporter-force-update reporter 1.0 "Subscribing ")
+	       (progress-reporter-done reporter)))))
+      (rudel-state-wait this '(idle) '(they-finalized) #'display-progress)))
+
+  ;; We receive a notification of our own subscription from the
+  ;; server. Consequently we do not add SELF to the list of subscribed
+  ;; users of DOCUMENT.
+  )
+
+(defmethod rudel-unsubscribe-from ((this rudel-obby-connection) document)
+  ""
+  ;; Delete the jupiter context for DOCUMENT.
+  (rudel-remove-context this document)
+
+  ;; Announce the end of our subscription to the server.
+  (with-slots (session) this
+    (with-slots (user-id) (oref session :self)
+      (with-slots ((doc-id :id) owner-id) document
+	(rudel-send this "obby_document"
+		    (format "%x %x" owner-id doc-id)
+		    "unsubscribe"
+		    (format "%x" user-id)))))
+
+  ;; We receive a notification of the end of our own subscription from
+  ;; the server. Consequently we do not remove SELF from the list of
+  ;; subscribed users of DOCUMENT.
+  )
+
+(defmethod rudel-local-insert ((this rudel-obby-connection)
+			       document position data)
+  ""
+  (rudel-local-operation
+   this
+   document
+   (jupiter-insert "insert" :from position :data data)))
+
+(defmethod rudel-local-delete ((this rudel-obby-connection)
+			       document position length)
+  ""
+  (rudel-local-operation
+   this
+   document
+   (jupiter-delete "delete" :from position :to (+ position length))))
+
+(defmethod rudel-local-operation ((this rudel-obby-connection)
+				  document operation)
+  "Handle OPERATION performed on DOCUMENT by sending a message through THIS connection."
+  ;; Convert character positions in OPERATION to byte positions, since
+  ;; the obby protocol works with byte positions, but Emacs uses
+  ;; character positions.
+  (with-slots (buffer) document
+    (rudel-obby-char->byte operation buffer))
+
+  ;; Find jupiter context for DOCUMENT.
+  (let ((context (rudel-find-context this document)))
+
+    ;; Notify the server of the operation.
+    (with-slots (owner-id (doc-id :id)) document
+      (with-slots (local-revision remote-revision) context
+	(apply #'rudel-send
+	       this
+	       "obby_document"
+	       (format "%x %x" owner-id doc-id)
+	       "record"
+	       (format "%x" local-revision)
+	       (format "%x" remote-revision)
+	       (rudel-operation->message operation))))
+
+      ;; Submit the operation to the jupiter context.
+      (jupiter-local-operation context operation))
+  )
+
+(defmethod rudel-remote-operation ((this rudel-obby-connection)
+				   document user
+				   remote-revision local-revision
+				   operation)
+  "Handle OPERATION received through THIS connection performed by USER on DOCUMENT."
+  (let* (;; Find jupiter context for DOCUMENT.
+	 (context     (rudel-find-context this document))
+	 ;; And transform the operation.
+	 (transformed (jupiter-remote-operation
+		       context
+		       remote-revision local-revision
+		       operation)))
+
+    ;; Convert byte positions in OPERATION to character positions,
+    ;; since the obby protocol works with byte positions, but Emacs
+    ;; uses character positions.
+    (with-slots (buffer) document
+      (rudel-obby-byte->char transformed buffer))  ;; TODO operation's responsibility?
+
+    ;; Apply the transformed operation to the document.
+    (rudel-remote-operation document user transformed))
+  )
+
+(provide 'rudel-obby-client)
+;;; rudel-obby-client.el ends here
diff --git a/emacs.d/lisp/rudel/obby/.svn/text-base/rudel-obby-debug.el.svn-base b/emacs.d/lisp/rudel/obby/.svn/text-base/rudel-obby-debug.el.svn-base
new file mode 100644
index 0000000..8f5f168
--- /dev/null
+++ b/emacs.d/lisp/rudel/obby/.svn/text-base/rudel-obby-debug.el.svn-base
@@ -0,0 +1,122 @@
+;;; rudel-obby-debug.el --- Debugging functions for obby backend
+;;
+;; Copyright (C) 2009 Jan Moringen
+;;
+;; Author: Jan Moringen <scymtym@users.sourceforge.net>
+;; Keywords: Rudel, obby, debugging
+;; X-RCS: $Id:$
+;;
+;; This program is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+;;
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; GNU General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with this program. If not, see <http://www.gnu.org/licenses>.
+
+
+;;; Commentary:
+;;
+;; Debugging functions for the obby backend.
+
+
+;;; History:
+;;
+;; 0.1 - Initial revision.
+
+
+;;; Code:
+;;
+
+(require 'eieio)
+
+(require 'rudel-debug)
+
+(require 'rudel-obby-util)
+
+
+;;; Variables
+;;
+
+(defvar rudel-obby-debug-old-state nil
+  "Saves state of state machines across one function call.")
+
+
+;;; Functions
+;;
+
+(defmethod rudel-send :before ((this rudel-obby-socket-owner)
+			       name &rest arguments)
+  "Print NAME and ARGUMENTS to debug stream."
+  (let ((message (apply #'rudel-obby-assemble-message
+			name arguments)))
+
+    (with-slots (socket) this
+      (rudel-debug-stream-insert
+       (rudel-debug-stream-name socket)
+       :sent
+       (concat  (substring message 0 (min (length message) 100))
+		(when (> (length message) 100)
+		  "..."))
+       (append (list name) arguments))))
+    )
+
+(defmethod rudel-receive :before ((this rudel-obby-socket-owner) data)
+  "Print DATA to debug stream."
+  (with-slots (socket) this
+    (rudel-debug-stream-insert
+     (rudel-debug-stream-name socket)
+     :received
+     (concat (substring data 0 (min (length data) 100))
+	     (when (> (length data) 100)
+	       "..."))))
+  )
+
+(defmethod rudel-message :before ((this rudel-obby-socket-owner)
+				  message)
+  "Print DATA to debug stream."
+  (let ((data (apply #'rudel-obby-assemble-message message)))
+
+    (with-slots (socket) this
+      (rudel-debug-stream-insert
+       (rudel-debug-stream-name socket)
+       :received-processed
+       (concat (substring data 0 (min (length data) 100))
+	       (when (> (length data) 100)
+		 "..."))
+       message)
+      ))
+  )
+
+(defmethod rudel-switch :before ((this rudel-obby-socket-owner)
+				 state &rest arguments)
+  "Store name of STATE for later printing."
+  (with-slots (state) this
+    (setq rudel-obby-debug-old-state
+	  (if state
+	      (object-name-string state)
+	    "#start")))
+  )
+
+(defmethod rudel-switch :after ((this rudel-obby-socket-owner)
+				state &rest arguments)
+  "Print STATE and ARGUMENTS to debug stream."
+  (with-slots (socket state) this
+    (let ((old-state rudel-obby-debug-old-state)
+	  (new-state (object-name-string state)))
+      (unless (string= old-state new-state)
+	(rudel-debug-stream-insert
+	 (rudel-debug-stream-name socket)
+	 :special
+	 (if arguments
+	     (format "%s -> %s %s" old-state new-state arguments)
+	   (format "%s -> %s" old-state new-state))))))
+  )
+
+(provide 'rudel-obby-debug)
+;;; rudel-obby-debug.el ends here
diff --git a/emacs.d/lisp/rudel/obby/.svn/text-base/rudel-obby-errors.el.svn-base b/emacs.d/lisp/rudel/obby/.svn/text-base/rudel-obby-errors.el.svn-base
new file mode 100644
index 0000000..689d4a8
--- /dev/null
+++ b/emacs.d/lisp/rudel/obby/.svn/text-base/rudel-obby-errors.el.svn-base
@@ -0,0 +1,65 @@
+;;; rudel-obby-errors.el --- Error data used in the obby Rudel backend
+;;
+;; Copyright (C) 2009 Jan Moringen
+;;
+;; Author: Jan Moringen <scymtym@users.sourceforge.net>
+;; Keywords: Rudel, obby, errors
+;; X-RCS: $Id:$
+;;
+;; This file is part of Rudel.
+;;
+;; Rudel is free software: you can redistribute it and/or modify it
+;; under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+;;
+;; Rudel is distributed in the hope that it will be useful, but
+;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+;; General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with Rudel. If not, see <http://www.gnu.org/licenses>.
+
+
+;;; Commentary:
+;;
+;; This file contains definitions of error conditions and numeric
+;; error codes used in the Rudel obby backend.
+
+
+;;; History:
+;;
+;; 0.1 - Initial revision.
+
+
+;;; Code:
+;;
+
+
+;;; Obby protocol error codes
+;;
+
+(defconst rudel-obby-error-username-invalid #x0001
+  "Error code for invalid username.")
+
+(defconst rudel-obby-error-username-in-use #x0002
+  "Error code for username already in use.")
+
+(defconst rudel-obby-error-color-in-use #x0100
+  "Error code for color already in use.")
+
+(defconst rudel-obby-error-wrong-global-password #x0101
+  "Error code for wrong global password.")
+
+(defconst rudel-obby-error-wrong-user-password #x0102
+  "Error code for wrong user password.")
+
+(defconst rudel-obby-error-protocol-version-mismatch #x0103
+  "Error code for protocol version mismatch.")
+
+(defconst rudel-obby-error-not-encrypted  #x0104
+  "Error code for not encrypted.")
+
+(provide 'rudel-obby-errors)
+;;; rudel-obby-errors.el ends here
diff --git a/emacs.d/lisp/rudel/obby/.svn/text-base/rudel-obby-server.el.svn-base b/emacs.d/lisp/rudel/obby/.svn/text-base/rudel-obby-server.el.svn-base
new file mode 100644
index 0000000..5bf1158
--- /dev/null
+++ b/emacs.d/lisp/rudel/obby/.svn/text-base/rudel-obby-server.el.svn-base
@@ -0,0 +1,798 @@
+;;; rudel-obby-server.el --- Server component of the Rudel obby backend
+;;
+;; Copyright (C) 2008, 2009 Jan Moringen
+;;
+;; Author: Jan Moringen <scymtym@users.sourceforge.net>
+;; Keywords: Rudel, obby, backend, server
+;; X-RCS: $Id:$
+;;
+;; This file is part of Rudel.
+;;
+;; Rudel is free software: you can redistribute it and/or modify it
+;; under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+;;
+;; Rudel is distributed in the hope that it will be useful, but
+;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+;; General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with Rudel. If not, see <http://www.gnu.org/licenses>.
+
+
+;;; Commentary:
+;;
+;; This file contains the server part of the obby backend for Rudel.
+;;
+;; It is implemented using one state machine (class
+;; `rudel-obby-client') for each client connection. These state
+;; machines have the following states:
+;;
+;; + new                  `rudel-obby-server-state-new'
+;; + encryption-negotiate `rudel-obby-server-state-encryption-negotiate'
+;; + before-join          `rudel-obby-server-state-before-join'
+;; + idle                 `rudel-obby-server-state-idle'
+
+
+;;; History:
+;;
+;; 0.2 - State machine.
+;;
+;; 0.1 - Initial revision.
+
+
+;;; Code:
+;;
+
+(eval-when-compile
+  (require 'cl))
+
+(require 'eieio)
+
+(require 'jupiter)
+
+(require 'rudel-state-machine)
+
+(require 'rudel-obby-errors)
+(require 'rudel-obby-util)
+(require 'rudel-obby-state)
+
+
+;;; Class rudel-obby-server-state-new
+;;
+
+(defclass rudel-obby-server-state-new
+  (rudel-obby-server-connection-state)
+  ()
+  "State in which new connections start out.")
+
+(defmethod rudel-enter ((this rudel-obby-server-state-new))
+  "Sends welcome messages to the client and starts the session
+timeout timer."
+  ;; Send greeting sequence to the client.
+  (rudel-send this
+	      "obby_welcome"
+	      (number-to-string rudel-obby-protocol-version))
+
+  ;; Switch to encryption negotiation state.
+  'encryption-negotiate)
+
+
+;;; Class rudel-obby-server-state-encryption-negotiate
+;;
+
+(defclass rudel-obby-server-state-encryption-negotiate
+  (rudel-obby-server-connection-state)
+  ()
+  "Encryption negotiation state.")
+
+(defmethod rudel-enter ((this rudel-obby-server-state-encryption-negotiate))
+  "Send net6 'encryption' message requesting to not enable encryption."
+  (rudel-send this "net6_encryption" "0")
+  nil)
+
+(defmethod rudel-obby/net6_encryption_ok
+  ((this rudel-obby-server-state-encryption-negotiate))
+  "Handle net6 'encryption_ok' message.
+Even if the client requests an encrypted connection, we cancel
+the negotiation."
+  (rudel-send this "net6_encryption_failed")
+  'before-join)
+
+(defmethod rudel-obby/net6_encryption_failed
+  ((this rudel-obby-server-state-encryption-negotiate))
+  "Handle net6 'encryption_failed' message.
+No action has to be taken, since the client simply proceeds after
+failed encryption negotiation."
+  'before-join)
+
+
+;;; Class rudel-obby-server-state-before-join
+;;
+
+(defclass rudel-obby-server-state-before-join
+  (rudel-obby-server-connection-state)
+  ()
+  "Waiting for client request joining the session.")
+
+(defmethod rudel-obby/net6_client_login
+  ((this rudel-obby-server-state-before-join) username color
+   &optional global-password user-password)
+  "Handle net6 'client_login' message."
+  (with-parsed-arguments ((color color))
+    (with-slots (server
+		 (client-id :id)
+		 user
+		 encryption) (oref this :connection)
+      ;; Make sure USERNAME and COLOR are valid.
+      (let ((error (rudel-check-username-and-color
+		    server username color)))
+	(if error
+	    ;; If USERNAME or COLOR are invalid, send the error code
+	    ;; to the client and stay in the current state.
+	    (progn
+	      (rudel-send this
+			  "net6_login_failed"
+			  (format "%x" error))
+	      nil)
+
+	  ;; Create a user object for this client and add it to the
+	  ;; server.
+	  (setq user (rudel-make-user
+		      server
+		      username client-id color encryption))
+	  (rudel-add-user server user)
+
+	  ;; Broadcast the join event to all clients (including the
+	  ;; new one).
+	  (with-slots ((name :object-name) color (user-id :user-id)) user
+	    (rudel-broadcast this (list 'exclude (oref this :connection))
+			     "net6_client_join"
+			     (format "%x" client-id)
+			     name
+			     "0"
+			     (format "%x" user-id)
+			     (rudel-obby-format-color color)))
+
+	  ;; Get the new client up to date:
+	  ;; - transmit user list
+	  ;;   - connected users
+	  ;;   - disconnected users
+	  ;; - transmit document list
+	  (with-slots (users clients documents) server
+	    ;; Send number of synchronization items: sum of numbers of
+	    ;; offline users and documents.
+	    (let ((number-of-items (+ (length users) (length documents))))
+	      (rudel-send this
+			  "obby_sync_init"
+			  (format "%x" number-of-items)))
+
+	    ;; Transmit list of connected users.
+	    (dolist (client clients)
+	      (with-slots ((client-id :id) user) client
+		(when user
+		  (with-slots ((name    :object-name)
+			       color
+			       (user-id :user-id)) user
+		    (rudel-send this
+				"net6_client_join"
+				(format "%x" client-id)
+				name
+				"0"
+				(format "%x" user-id)
+				(rudel-obby-format-color color))))))
+
+	    ;; Transmit list of disconnected users.
+	    (let ((offline-users (remove-if #'rudel-connected users)))
+	      (dolist (user offline-users)
+		(with-slots ((name :object-name) user-id color) user
+		  (rudel-send this
+			      "obby_sync_usertable_user"
+			      (format "%x" user-id)
+			      name
+			      (rudel-obby-format-color color)))))
+
+	    ;; Transmit document list
+	    (dolist (document documents)
+	      (with-slots ((name      :object-name)
+			   (doc-id    :id)
+			   owner-id
+			   suffix
+			   subscribed) document
+		(apply #'rudel-send
+		       this
+		       "obby_sync_doclist_document"
+		       (format "%x" owner-id)
+		       (format "%x" doc-id)
+		       name
+		       (format "%x" suffix)
+		       "UTF-8"
+		       (mapcar
+			(lambda (user1) ;; TODO we could use `user' here, but there is a bug in cl
+			  (format "%x" (rudel-id user1)))
+			subscribed)))))
+
+	  (rudel-send this "obby_sync_final")
+	  'idle))))
+  )
+
+
+;;; Class rudel-obby-server-state-idle
+;;
+
+(defclass rudel-obby-server-state-idle
+  (rudel-obby-server-connection-state)
+  ()
+  "Idle state of a server connection.
+
+The connection enters this state when all setup work is finished,
+the client has joined the session and no operation is in
+progress. In this state, the connection waits for new messages
+from the client that initiate operations. Simple (which means
+stateless in this case) operations are performed without leaving
+the idle state.")
+
+(defmethod rudel-obby/obby_user_colour
+  ((this rudel-obby-server-state-idle) color-)
+  "Handle obby 'user_colour' message.
+This method is called when the connected user requests a change
+of her color to COLOR."
+  (with-parsed-arguments ((color- color))
+    (with-slots (user) (oref this :connection)
+      (with-slots (color (user-id :user-id)) user
+	;; Set color slot value.
+	(setq color color-)
+
+	;; Run change hook.
+	(object-run-hook-with-args user 'change-hook)
+
+	(rudel-broadcast this (list 'exclude (oref this :connection))
+			 "obby_user_colour"
+			 (format "%x" user-id)
+			 (rudel-obby-format-color color)))))
+  nil)
+
+(defmethod rudel-obby/obby_document_create
+  ((this rudel-obby-server-state-idle)
+   doc-id name encoding content)
+  "Handle obby 'document_create' message."
+  (with-parsed-arguments ((doc-id   number)
+			  (encoding coding-system))
+    (with-slots (user server) (oref this :connection)
+      (with-slots ((user-id :user-id)) user
+	;; Create a (hidden) buffer for the new document.
+	(let* ((buffer         (get-buffer-create
+				(generate-new-buffer-name
+				 (concat " *"  name "*"))))
+	       ;; Create the new document object
+	       (document       (rudel-obby-document
+				name
+				:buffer     buffer
+				:subscribed (list user)
+				:id         doc-id
+				:owner-id   user-id
+				:suffix     1)))
+
+	  ;; Initialize the buffer's content
+	  (with-current-buffer buffer
+	    (insert content))
+
+	  (with-slots (suffix) document
+	    ;; Determine an appropriate suffix to provide an unique
+	    ;; name for the new document.
+	    (while (rudel-find-document server
+					(if (= suffix 1)
+					    name
+					  (format "%s<%d>" name suffix))
+					#'string= #'rudel-unique-name)
+	      (incf suffix))
+
+	    ;; Add the document to the server's document list
+	    (rudel-add-document server document)
+
+	    ;; Maybe notify the creating client of the changed suffix.
+	    (unless (= suffix 1)
+	      (rudel-send this
+			  "obby_document"
+			  (format "%x %x" user-id doc-id)
+			  "rename"
+			  (format "%x" user-id)
+			  name
+			  (format "%x" suffix)))
+
+	    ;; Notify other clients of the new document
+	    (rudel-broadcast this (list 'exclude  (oref this :connection))
+			     "obby_document_create"
+			     (format "%x" user-id)
+			     (format "%x" doc-id)
+			     name
+			     (format "%x" suffix)
+			     (upcase (symbol-name encoding))))
+
+	  ;; Add a jupiter context for (THIS DOCUMENT).
+	  (rudel-add-context server (oref this :connection) document))))
+    nil)
+  )
+
+(defmethod rudel-obby/obby_document
+  ((this rudel-obby-server-state-idle) doc-id action &rest arguments)
+  "Handle obby 'document' messages."
+  (with-parsed-arguments ((doc-id document-id))
+    ;; Locate the document based on owner id and document id
+    (let ((document (with-slots (server) (oref this :connection)
+		      (rudel-find-document server doc-id
+					   #'equal #'rudel-both-ids))))
+      (rudel-obby-dispatch this action
+			   (append (list document) arguments)
+			   "rudel-obby/obby_document/")))
+  )
+
+(defmethod rudel-obby/obby_document/subscribe
+  ((this rudel-obby-server-state-idle) document user-id)
+  "Handle 'subscribe' submessage of obby 'document' message."
+  (with-parsed-arguments ((user-id number))
+    (let ((user (with-slots (server) (oref this :connection)
+		  (rudel-find-user server user-id
+				   #'= #'rudel-id))))
+      (with-slots (owner-id (doc-id :id) subscribed buffer) document
+
+	;; Track subscription, handle duplicate subscription requests.
+	(when (memq user subscribed)
+	  (error "User `%s' already subscribed to document `%s'"
+		 (object-name user) (object-name document)))
+	(rudel-add-user document user)
+
+	;; Synchronize the buffer content to the client.
+	(with-current-buffer buffer
+	  ;; Send overall buffer size
+	  (rudel-send this
+		      "obby_document"
+		      (format "%x %x" owner-id doc-id)
+		      "sync_init"
+		      (format "%x" (1- (position-bytes (point-max)))))
+
+	  ;; Send buffer chunks with author ids
+	  (dolist (chunk (rudel-chunks document))
+	    (multiple-value-bind (from to author) chunk
+	      (let ((string (buffer-substring (+ from 1) (+ to 1))))
+		(rudel-send this
+			    "obby_document"
+			    (format "%x %x" owner-id doc-id)
+			    "sync_chunk"
+			    string
+			    (format "%x"
+				    (if author
+					(oref author :user-id)
+				      0)))))))
+
+	;; Notify clients of the new subscription (including our own
+	;; client, who requested the subscription).
+	(with-slots ((user-id :user-id)) user
+	  (rudel-broadcast this nil
+			   "obby_document"
+			   (format "%x %x" owner-id doc-id)
+			   "subscribe"
+			   (format "%x" user-id)))))
+
+    ;; Add a jupiter context for (THIS document).
+    (with-slots (server) (oref this :connection)
+      (rudel-add-context server (oref this :connection) document))
+    nil)
+  )
+
+(defmethod rudel-obby/obby_document/unsubscribe
+  ((this rudel-obby-server-state-idle) document user-id)
+  "Handle 'unsubscribe' submessage of 'obby_document' message."
+  (with-parsed-arguments ((user-id number))
+    (let ((user (with-slots (server) (oref this :connection)
+		  (rudel-find-user server user-id
+				   #'= #'rudel-id))))
+      (with-slots (owner-id (doc-id :id) subscribed) document
+
+	;; Track subscription, handle invalid unsubscribe requests
+	(unless (memq user subscribed)
+	  (error "User `%s' not subscribed to document `%s'"
+		 (object-name user) (object-name document)))
+	(rudel-remove-user document user)
+
+	;; Notify clients of the canceled subscription (including our
+	;; own client, who requested being unsubscribed).
+	(with-slots ((user-id :user-id)) user
+	  (rudel-broadcast this nil
+			   "obby_document"
+			   (format "%x %x" owner-id doc-id)
+			   "unsubscribe"
+			   (format "%x" user-id))))
+
+      ;; Remove jupiter context for (THIS DOCUMENT).
+      (with-slots (server) (oref this :connection)
+	(rudel-remove-context server (oref this :connection) document)))
+    nil)
+  )
+
+(defmethod rudel-obby/obby_document/record
+  ((this rudel-obby-server-state-idle)
+   document local-revision remote-revision action &rest arguments)
+  "Handle 'record' submessages of 'obby_document' message."
+  (with-parsed-arguments ((local-revision  number)
+			  (remote-revision number))
+    ;; Dispatch to specialized operation handlers.
+    (rudel-obby-dispatch
+     this action
+     (append (list document local-revision remote-revision)
+	     arguments)
+     "rudel-obby/obby_document/record/"))
+  )
+
+(defmethod rudel-obby/obby_document/record/ins
+  ((this rudel-obby-server-state-idle)
+   document local-revision remote-revision position data)
+  "Handle 'ins' submessage of 'record' submessages of 'obby_document' message."
+  (with-parsed-arguments ((position number))
+    ;; Construct the operation object and process it.
+    (rudel-remote-operation
+     (oref this :connection) document
+     remote-revision local-revision
+     (jupiter-insert
+      (format "insert-%d-%d"
+	      remote-revision local-revision)
+      :from position
+      :data data))
+    nil)
+  )
+
+(defmethod rudel-obby/obby_document/record/del
+  ((this rudel-obby-server-state-idle)
+   document local-revision remote-revision position length)
+  "Handle 'del' submessage of 'record' submessages of 'obby_document' message."
+  (with-parsed-arguments ((position number)
+			  (length   number))
+    ;; Construct the operation object and process it.
+    (rudel-remote-operation
+     (oref this :connection) document
+     remote-revision local-revision
+     (jupiter-delete
+      (format "delete-%d-%d"
+	      remote-revision local-revision)
+      :from position
+      :to   (+ position length)))
+    nil)
+  )
+
+
+;;; Client connection states.
+;;
+
+(defvar rudel-obby-server-connection-states
+  '((new                  . rudel-obby-server-state-new)
+    (encryption-negotiate . rudel-obby-server-state-encryption-negotiate)
+    (before-join          . rudel-obby-server-state-before-join)
+    (idle                 . rudel-obby-server-state-idle))
+  "Name symbols and classes of connection states.")
+
+
+;;; Class rudel-obby-client
+;;
+
+(defclass rudel-obby-client (rudel-obby-socket-owner
+			     rudel-state-machine)
+  ((server     :initarg  :server
+	       :type     rudel-obby-server
+	       :documentation
+	       "")
+   (id         :initarg  :id
+	       :type     integer
+	       :accessor rudel-id
+	       :documentation
+	       "")
+   (user       :initarg  :user
+	       :type     (or rudel-obby-user null)
+	       :initform nil
+	       :documentation
+	       "")
+   (encryption :initarg  :encryption
+	       :type     boolean
+	       :documentation
+	       ""))
+  "Each object of this class represents one client, that is
+connected to the server. This object handles all direct
+communication with the client, while broadcast messages are
+handled by the server.")
+
+(defmethod initialize-instance ((this rudel-obby-client) &rest slots)
+  "Initialize slots of THIS and register state machine states."
+  ;; Initialize slots of THIS
+  (when (next-method-p)
+    (call-next-method))
+
+  ;; Register states.
+  (rudel-register-states this rudel-obby-server-connection-states)
+  )
+
+(defmethod rudel-register-state ((this rudel-obby-client) symbol state)
+  "Register SYMBOL and STATE and set connection slot of STATE."
+  ;; Associate THIS connection to STATE.
+  (oset state :connection this)
+
+  ;; Register STATE.
+  (call-next-method))
+
+(defmethod rudel-end ((this rudel-obby-client))
+  ""
+  (rudel-disconnect this))
+
+(defmethod rudel-close ((this rudel-obby-client))
+  ""
+  (with-slots (server) this
+    (rudel-remove-client server this)))
+
+(defmethod rudel-message ((this rudel-obby-client) message)
+  "Dispatch MESSAGE to the active state of THIS state machine."
+  ;; Dispatch message to state
+  (rudel-accept this message))
+
+(defmethod rudel-broadcast ((this rudel-obby-client)
+			    receivers name &rest arguments)
+  "Broadcast message NAME with arguments ARGUMENTS to RECEIVERS."
+  (with-slots (server) this
+    (apply #'rudel-broadcast server receivers name arguments)))
+
+(defmethod rudel-remote-operation ((this rudel-obby-client)
+				   document
+				   local-revision remote-revision
+				   operation)
+  "Execute and relay OPERATION on DOCUMENT."
+  (with-slots (server user) this
+    ;; Transform OPERATION and find clients that need to receive
+    ;; notifications.
+    (let* ((context     (rudel-find-context server this document))
+	   (transformed (jupiter-remote-operation
+			 context
+			 local-revision remote-revision
+			 operation))
+	   (receivers   (rudel-subscribed-clients-not-self
+			 this document)))
+
+      ;; Relay change notification to other clients. We use
+      ;; TRANSFORMED before the byte -> char conversion which is what
+      ;; the receivers expect.
+      (with-slots (user-id) user
+	(with-slots (owner-id (doc-id :id)) document
+	  ;; Construct and send messages to all receivers individually
+	  ;; since the contents of the messages depends on the state
+	  ;; of the jupiter context associated the respective
+	  ;; receiver.
+	  (dolist (receiver receivers)
+
+	    ;; Find the jupiter context for RECEIVER and use its
+	    ;; revision information.
+	    (let ((context (rudel-find-context server receiver document)))
+	      ;; Construct and send one message.
+	      (with-slots (local-revision remote-revision) context
+		(apply #'rudel-send
+		       receiver
+		       "obby_document"
+		       (format "%x %x" owner-id doc-id)
+		       "record"
+		       (format "%x" user-id)
+		       (format "%x" local-revision)
+		       (format "%x" remote-revision)
+		       (rudel-operation->message transformed)))
+
+	      ;; Submit the operation to the jupiter context.
+	      (jupiter-local-operation context transformed)))))
+
+      ;; Incorporate change into DOCUMENT (the server-side
+      ;; document). We have to convert bytes -> chars before we can do
+      ;; this.
+      (with-slots (buffer) document
+	(rudel-obby-byte->char transformed buffer))
+
+      (rudel-remote-operation document user transformed)))
+  )
+
+(defmethod rudel-subscribed-clients-not-self ((this rudel-obby-client)
+					      document)
+  "Return a list of clients subscribed to DOCUMENT excluding THIS."
+  (with-slots (clients) (oref this :server)
+    (with-slots (subscribed) document
+      (remove-if
+       (lambda (client)
+	 (with-slots (user) client
+	   (or (eq client this)
+	       (not (memq user subscribed)))))
+       clients)))
+  )
+
+
+;;; Class rudel-obby-server
+;;
+
+(defclass rudel-obby-server (rudel-server-session
+			     rudel-socket-owner)
+  ((clients        :initarg  :clients
+		   :type     list
+		   :initform nil
+		   :documentation
+		   "")
+   (next-client-id :initarg  :next-client-id
+		   :type     integer
+		   :initform 1
+		   :documentation
+		   "")
+   (next-user-id   :initarg  :next-user-id
+		   :type     integer
+		   :initform 1
+		   :documentation
+		   "")
+   (contexts       :initarg  :contexts
+		   :type     hash-table
+		   :documentation
+		   ""))
+  "Class rudel-obby-server ")
+
+(defmethod initialize-instance ((this rudel-obby-server) &rest slots)
+  ""
+  (when (next-method-p)
+    (call-next-method))
+
+  (with-slots (contexts) this
+    (setq contexts (make-hash-table :test 'equal))))
+
+(defmethod rudel-end ((this rudel-obby-server))
+  ""
+  (rudel-disconnect this))
+
+(defmethod rudel-broadcast ((this rudel-obby-server)
+			    receivers name &rest arguments)
+  "Send a message of type NAME with arguments ARGUMENTS to RECEIVERS.
+
+RECEIVERS can be a object derived from rudel-obby-client, a list
+of such objects or a list with car 'exclude and cdr a list of
+such objects derived from rudel-obby-client."
+  ;; Construct list of receivers.
+  (let ((receiver-list
+	 (cond
+	  ;; If RECEIVERS is nil, the message should be broadcast to
+	  ;; all clients.
+	  ((null receivers) (oref this :clients))
+	  ;; If RECEIVERS is a (non-empty) list of rudel-obby-client
+	  ;; (or derived) objects, treat it as a list of receivers.
+	  ((and (listp receivers)
+		(rudel-obby-client-child-p (car receivers)))
+	   receivers)
+	  ;; If RECEIVERS is a (non-empty) list with cdr equal to
+	  ;; 'exclude treat it as a list of receivers to exclude.
+	  ((and (listp receivers)
+		(eq (car receivers) 'exclude))
+	   (with-slots (clients) this
+	     (set-difference clients (cdr receivers)
+			     :key #'rudel-id)))
+	  ;; If RECEIVERS is a single rudel-obby-client (or derived)
+	  ;; object, send the message to that client.
+	  ((rudel-obby-client-child-p receivers)
+	   (list receivers))
+	  ;;
+	  (t (signal 'wrong-type-argument (type-of receivers))))))
+
+    ;; Send message to receivers.
+    (dolist (receiver receiver-list)
+      (apply #'rudel-send receiver name arguments)))
+  )
+
+(defmethod rudel-make-user ((this rudel-obby-server)
+			    name client-id color encryption)
+  ""
+  (with-slots (next-user-id) this
+    (let ((user (rudel-obby-user name
+                 :color      color
+		 :client-id  client-id
+		 :user-id    next-user-id
+		 :connected  t
+		 :encryption encryption)))
+      (incf next-user-id)
+      user))
+  )
+
+(defmethod rudel-check-username-and-color ((this rudel-obby-server)
+					   username color)
+  "Check whether USERNAME and COLOR are valid.
+USERNAME must not be empty and must not be used by another
+user. COLOR has to be sufficiently different from used colors."
+  (cond
+   ;; The empty user name is not allowed
+   ((string= username "")
+    rudel-obby-error-username-invalid)
+
+   ;; Make sure the user name is not already in use.
+   ((rudel-find-user this username
+		     #'string= #'object-name-string)
+    rudel-obby-error-username-in-use)
+
+   ;; Make sure the color is sufficiently dissimilar to all used
+   ;; colors.
+   ((rudel-find-user this color
+		     (lambda (left right)
+		       (< (color-distance left right) 20000)) ;; TODO constant
+		     #'rudel-color)
+    rudel-obby-error-color-in-use))
+  )
+
+(defmethod rudel-add-client ((this rudel-obby-server)
+			     client-socket)
+  ""
+  (with-slots (next-client-id clients) this
+    (let ((client (rudel-obby-client (process-name client-socket)
+		   :server     this
+		   :socket     client-socket
+		   :id         next-client-id
+		   :encryption nil)))
+      (push client clients))
+    (incf next-client-id))
+  )
+
+(defmethod rudel-remove-client ((this rudel-obby-server)
+				client)
+  ""
+  (with-slots ((client-id :id) user) client
+    ;; Broadcast the part event to all remaining clients.
+    (rudel-broadcast this (list 'exclude client)
+		     "net6_client_part"
+		     (format "%x" client-id))
+
+    ;; If the client has an associated user object, set the status of
+    ;; the user object to offline.
+    (when user
+      ;; Set slot value.
+      (with-slots (connected) user
+	(setq connected nil))
+
+      ;; Run change hook.
+      (object-run-hook-with-args user 'change-hook)))
+
+  (object-remove-from-list this :clients client)
+  )
+
+(defmethod rudel-find-context ((this rudel-obby-server) client document)
+  "Return the jupiter context associated to (CLIENT DOCUMENT) in THIS."
+  (with-slots (contexts) this
+    (gethash (rudel-obby-context-key client document) contexts)))
+
+(defmethod rudel-add-context ((this rudel-obby-server) client document)
+  "Add a jupiter context for (CLIENT DOCUMENT) to THIS."
+  (with-slots (contexts) this
+    (with-slots ((client-id :id)) client
+      (with-slots ((doc-name :object-name)) document
+	(puthash
+	 (rudel-obby-context-key client document)
+	 (jupiter-context (format "%d-%s" client-id doc-name))
+	 contexts))))
+  )
+
+(defmethod rudel-remove-context ((this rudel-obby-server) client document)
+  "Remove the jupiter context associated to (CLIENT DOCUMENT) from THIS."
+  (with-slots (contexts) this
+    (remhash
+     (rudel-obby-context-key client document)
+     contexts)))
+
+(defun rudel-obby-context-key (client document)
+  "Generate hash key based on CLIENT and DOCUMENT."
+  (with-slots ((client-id :id)) client
+    (with-slots ((doc-id :id)) document
+      (list client-id doc-id))))
+
+(defmethod object-print ((this rudel-obby-server) &rest strings)
+  "Print THIS with number of clients."
+  (with-slots (clients) this
+    (apply #'call-next-method
+	   this
+	   (format " clients: %d"
+		   (length clients))
+	   strings))
+  )
+
+(provide 'rudel-obby-server)
+;;; rudel-obby-server.el ends here
diff --git a/emacs.d/lisp/rudel/obby/.svn/text-base/rudel-obby-state.el.svn-base b/emacs.d/lisp/rudel/obby/.svn/text-base/rudel-obby-state.el.svn-base
new file mode 100644
index 0000000..a190967
--- /dev/null
+++ b/emacs.d/lisp/rudel/obby/.svn/text-base/rudel-obby-state.el.svn-base
@@ -0,0 +1,169 @@
+;;; rudel-obby-state.el --- Base class for states used in the obby backend
+;;
+;; Copyright (C) 2009 Jan Moringen
+;;
+;; Author: Jan Moringen <scymtym@users.sourceforge.net>
+;; Keywords: Rudel, obby, state machine
+;; X-RCS: $Id:$
+;;
+;; This file is part of Rudel.
+;;
+;; Rudel is free software: you can redistribute it and/or modify it
+;; under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+;;
+;; Rudel is distributed in the hope that it will be useful, but
+;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+;; General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with Rudel. If not, see <http://www.gnu.org/licenses>.
+
+
+;;; Commentary:
+;;
+;; This file contains a base class for finite state machine states
+;; used in the obby backend.
+
+
+;;; History:
+;;
+;; 0.1 - Initial revision
+
+
+;;; Code:
+;;
+
+(require 'eieio)
+
+(require 'rudel-util)
+(require 'rudel-state-machine)
+
+(require 'rudel-obby-util)
+
+
+;;; Class rudel-obby-state
+;;
+
+(defclass rudel-obby-state (rudel-state)
+  ((connection :initarg :connection
+	       :type    rudel-obby-socket-owner
+	       :documentation
+	       "Connection object that uses the state."))
+  "Base class for state classes used in the obby backend."
+  :abstract t)
+
+(defmethod rudel-enter ((this rudel-obby-state))
+  "Default behavior is doing nothing when entering a state."
+  nil)
+
+(defmethod rudel-leave ((this rudel-obby-state))
+  "Default behavior is doing nothing when leaving a state.")
+
+(defmethod rudel-accept ((this rudel-obby-state) message)
+  "Dispatch to appropriate handler based on MESSAGE.
+Display a warning if no such handler is found."
+  ;; Try to dispatch to the correct message handler. If there is none,
+  ;; warn.
+  (let ((name      (car message))
+	(arguments (cdr message)))
+    (condition-case error
+	;; Try to dispatch
+	(rudel-dispatch this "rudel-obby/" name arguments)
+      ;; Warn if we failed to locate or execute the method. Return nil
+      ;; in this case, so we remain in the current state.
+      (rudel-dispatch-error
+       (progn
+	 (display-warning
+	  '(rudel obby)
+	  (format "%s: no method (%s: %s): `%s/%s'; arguments: %s"
+		  (object-print this) (car error) (cdr error)
+		  "rudel-obby" name arguments)
+	  :debug)
+	 nil))))
+  )
+
+(defmethod rudel-send ((this rudel-obby-state) &rest args)
+  "Send ARGS through the connection associated with THIS."
+  (with-slots (connection) this
+    (apply #'rudel-send connection args)))
+
+
+;;; Class rudel-obby-client-connection-state
+;;
+
+(defclass rudel-obby-client-connection-state (rudel-obby-state)
+  ()
+  "Base class for state classes used by obby client connections."
+  :abstract t)
+
+(defmethod rudel-obby/net6_ping ((this rudel-obby-client-connection-state))
+  "Handle net6 'ping' message."
+  (rudel-send this "net6_pong")
+  nil)
+
+
+;;; Class rudel-obby-server-connection-state
+;;
+
+(defclass rudel-obby-server-connection-state (rudel-obby-state)
+  ()
+  "Base class for server connection states."
+  :abstract t)
+
+(defmethod rudel-broadcast ((this rudel-obby-server-connection-state)
+			    receivers name &rest arguments)
+  "Broadcast message NAME with arguments ARGUMENTS to RECEIVERS."
+  (with-slots (connection) this
+    (apply #'rudel-broadcast connection receivers name arguments)))
+
+
+;;; Class rudel-obby-document-handler
+;;
+
+(defclass rudel-obby-document-handler ()
+  ()
+  "Mixin class that provides ability to process submessages of
+  obby 'document' messages.")
+
+(defmethod rudel-obby/obby_document
+  ((this rudel-obby-document-handler) doc-id action &rest arguments)
+  "Handle obby 'document' message family."
+  ;; Try to dispatch to the correct message handler. If there is none,
+  ;; warn.
+  (with-parsed-arguments ((doc-id document-id))
+    ;; Locate the document based on owner id and document id.
+    (let ((document (with-slots (connection) this
+		      (with-slots (session) connection
+			(rudel-find-document session doc-id
+					     #'equal #'rudel-both-ids)))))
+      (if document
+	  (condition-case error
+	      ;; Try to dispatch
+	      (rudel-dispatch this "rudel-obby/obby_document/" action
+			      (cons document arguments))
+	    ;; Warn if we failed to locate or execute the
+	    ;; method. Return nil in this case, so we remain in the
+	    ;; current state.
+	    (rudel-dispatch-error
+	     (progn
+	       (display-warning
+		'(rudel obby)
+		(format "%s: no method (%s: %s): `%s:%s'; arguments: %s"
+			(object-print this) (car error) (cdr error)
+			"rudel-obby/obby_document/" action arguments)
+		:debug)
+	       nil)))
+	;; If we did not find the document, warn.
+	(progn
+	  (display-warning
+	   '(rudel obby)
+	   (format "Document not found: %s" doc-id)
+	   :debug)
+	  nil))))
+  )
+
+(provide 'rudel-obby-state)
+;;; rudel-obby-state.el ends here
diff --git a/emacs.d/lisp/rudel/obby/.svn/text-base/rudel-obby-util.el.svn-base b/emacs.d/lisp/rudel/obby/.svn/text-base/rudel-obby-util.el.svn-base
new file mode 100644
index 0000000..faefe70
--- /dev/null
+++ b/emacs.d/lisp/rudel/obby/.svn/text-base/rudel-obby-util.el.svn-base
@@ -0,0 +1,314 @@
+;;; rudel-obby-util.el --- Miscellaneous functions for the Rudel obby backend
+;;
+;; Copyright (C) 2008, 2009 Jan Moringen
+;;
+;; Author: Jan Moringen <scymtym@users.sourceforge.net>
+;; Keywords: Rudel, obby, backend, miscellaneous
+;; X-RCS: $Id:$
+;;
+;; This file is part of Rudel.
+;;
+;; Rudel is free software: you can redistribute it and/or modify it
+;; under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+;;
+;; Rudel is distributed in the hope that it will be useful, but
+;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+;; General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with Rudel. If not, see <http://www.gnu.org/licenses>.
+
+
+;;; Commentary:
+;;
+;;
+
+
+;;; History:
+;;
+;; 0.1 - Initial revision.
+
+
+;;; Code:
+;;
+
+(eval-when-compile
+  (require 'cl))
+
+(require 'eieio)
+
+(require 'rudel)
+(require 'rudel-util)
+
+(require 'jupiter)
+
+
+;;; Class rudel-obby-socket-owner
+;;
+
+(defclass rudel-obby-socket-owner (rudel-socket-owner)
+  ((buffer :initarg  :buffer
+	   :type     (or null string)
+	   :initform nil
+	   :documentation
+	   "Stores message fragments until complete messages can
+be assembled."))
+  "This class adds functions for sending and receiving obby
+messages to the base class rudel-socket-owner.")
+
+(defmethod rudel-send ((this rudel-obby-socket-owner)
+		       name &rest arguments)
+  "Send obby message NAME with arguments ARGUMENTS through the socket associated to THIS."
+  (with-slots (socket) this
+    (rudel-obby-send socket name arguments)))
+
+(defmethod rudel-receive ((this rudel-obby-socket-owner) data)
+  "Reassemble lines in DATA received on the socket associated with THIS and call message handler."
+  ;; Assemble fragmented lines.
+  (with-slots (buffer) this
+    (rudel-assemble-line-fragments data buffer))
+
+  ;; Process all available lines.
+  (rudel-loop-lines data line
+    ;; `rudel-message' has to dispatch message to an appropriate
+    ;; handler.
+    (let ((message (rudel-obby-parse-message line)))
+      (rudel-message this message)))
+  )
+
+(defgeneric rudel-message ((this rudel-obby-socket-owner) message)
+  "Called when a message arrives.
+Should be implemented in derived classes.")
+
+
+;;; Message serialization
+;;
+
+(defgeneric rudel-operation->message ((this jupiter-operation))
+  "Generate a list obby message components from THIS operation.")
+
+(defmethod rudel-operation->message ((this jupiter-insert))
+  "Serialize THIS insert operation."
+  (with-slots (from data) this
+    (list "ins" (format "%x" from) data)))
+
+(defmethod rudel-operation->message ((this jupiter-delete))
+  "Serialize THIS delete operation."
+  (with-slots (from length) this
+    (list "del" (format "%x" from) (format "%x" length))))
+
+(defmethod rudel-operation->message ((this jupiter-compound))
+  "Serialize THIS compound operation."
+  (with-slots (children) this
+    (apply #'append
+	   (list "split" )
+	   (mapcar #'rudel-operation->message children))))
+
+(defmethod rudel-operation->message ((this jupiter-nop))
+  "Serialize THIS nop operation."
+  (list "nop"))
+
+(defun rudel-message->operation (message local-revision remote-revision)
+  "Construct an operation object from MESSAGE and LOCAL-REVISION and REMOTE-REVISION.
+LOCAL-REVISION and REMOTE-REVISION are only used in the
+construction of the name of the new operation. "
+  (let ((type (car message)))
+    (cond
+
+     ;; Insert operation
+     ((string= type "ins")
+      (let ((position-numeric (string-to-number (nth 1 message) 16))
+	    (data             (nth 2 message)))
+	(jupiter-insert
+	 (format "insert-%d-%d"
+		 remote-revision local-revision)
+	 :from position-numeric
+	 :data data)))
+
+     ;; Delete operation
+     ((string= type "del")
+      (let ((position-numeric (string-to-number (nth 1 message) 16))
+	    (length-numeric   (string-to-number (nth 2 message) 16)))
+	(jupiter-delete
+	 (format "delete-%d-%d"
+		 remote-revision local-revision)
+	 :from position-numeric
+	 :to   (+ position-numeric length-numeric))))
+
+     ;; Compound operation
+     ((string= type "split")
+      (let* ((rest   (cdr message))
+	     (offset (position-if
+		       (lambda (item)
+			 (member* item '("ins" "del" "nop")
+				  :test #'string=))
+		       rest
+		       :start 1))
+	     (first  (subseq rest 0 offset))
+	     (second (subseq rest offset)))
+	(jupiter-compound
+	 (format "compound-%d-%d"
+		 remote-revision local-revision)
+	 :children
+	 (list (rudel-message->operation
+		first local-revision remote-revision)
+	       (rudel-message->operation
+		second local-revision remote-revision)))))
+
+     ;; No operation
+     ((string= type "nop")
+      (jupiter-nop
+       (format "nop-%d-%d"
+	       remote-revision local-revision)))
+
+     ;; Unknown operation type
+     (t (error "Unknown document record type: `%s'" type))))
+  )
+
+
+;;; Character <-> byte position conversion
+;;
+
+(defgeneric rudel-obby-char->byte ((this jupiter-operation) buffer)
+  "Convert character positions and lengths in THIS to bytes.")
+
+(defmethod rudel-obby-char->byte ((this jupiter-insert) buffer)
+  "Convert character positions and lengths in THIS insert to bytes."
+  (with-slots (from) this
+    (with-current-buffer buffer
+      (setq from (- (position-bytes (+ from 1)) 1)))))
+
+(defmethod rudel-obby-char->byte ((this jupiter-delete) buffer)
+ "Convert character positions and lengths in THIS delete to bytes."
+  (with-slots (from to length) this
+    (let ((old-from (+ from 1))
+	  (old-to   (+ to   1)))
+      (with-current-buffer buffer
+	(destructuring-bind (change-from change-to string)
+	    rudel-buffer-change-workaround-data
+	  (setq from   (- (position-bytes old-from) 1)
+		length (string-bytes
+			(substring string
+				   (- old-from change-from)
+				   (- old-to   change-from))))))))
+  )
+
+(defmethod rudel-obby-char->byte ((this jupiter-compound) buffer)
+  "Convert character positions and lengths in THIS compound to bytes.."
+  (with-slots (children) this
+    (mapc
+     (lambda (child)
+       (rudel-obby-char->byte child buffer))
+     children))
+  )
+
+(defmethod rudel-obby-char->byte ((this jupiter-nop) buffer)
+  "Nothing to convert if THIS is a nop.")
+
+(defgeneric rudel-obby-byte->char ((this jupiter-operation) buffer)
+  "Convert byte positions and lengths in THIS to character positions.")
+
+(defmethod rudel-obby-byte->char ((this jupiter-insert) buffer)
+  "Convert byte positions and lengths in THIS insert to character positions."
+  (with-slots (from) this
+    (with-current-buffer buffer
+      (setq from (- (byte-to-position (+ from 1)) 1)))))
+
+(defmethod rudel-obby-byte->char ((this jupiter-delete) buffer)
+  "Convert byte positions and lengths in THIS delete to character positions."
+  (with-slots (from to length) this
+    (let ((old-from   from)
+	  (old-length length))
+      (with-current-buffer buffer
+	(setq from (- (byte-to-position (+ old-from 1)) 1)
+	      to   (- (byte-to-position (+ old-from old-length 1)) 1)))))
+  )
+
+(defmethod rudel-obby-byte->char ((this jupiter-compound) buffer)
+  "Convert byte positions and lengths in THIS compound to character positions."
+  (with-slots (children) this
+    (mapc
+     (lambda (child)
+       (rudel-obby-byte->char child buffer))
+     children))
+  )
+
+(defmethod rudel-obby-byte->char ((this jupiter-nop) buffer)
+  "Nothing to convert if THIS is a nop.")
+
+
+;;; Miscellaneous functions
+;;
+
+(defun rudel-obby-dispatch (object name arguments &optional prefix)
+  "Call method starting with PREFIX and ending in NAME of OBJECT with ARGUMENTS.
+When PREFIX is not specified, \"rudel-obby/\" is used."
+  ;; Default prefix.
+  (unless prefix
+    (setq prefix "rudel-obby/"))
+
+  ;; Construct a matching symbol.
+  (let ((method (intern-soft (concat prefix name))))
+    ;; If we found a suitable method, run it; Otherwise warn and do
+    ;; nothing.
+    (unless (and method
+		 (condition-case error
+		     ;; Try to call METHOD. If successful, always
+		     ;; return t.
+		     (progn
+		       (apply method object arguments)
+		       t)
+		   ;; Warn only when the condition is
+		   ;; 'no-method-definition' and refers to METHOD,
+		   ;; otherwise continue unwinding.
+		   (no-method-definition
+		    (if (eq method (cadr error))
+			nil
+		      (signal (car error) (cdr error))))))
+      (display-warning
+       '(rudel obby)
+       (format "%s: in context `%s': no method: `%s'; arguments: %s"
+	       (object-name-string object) prefix name arguments)
+       :debug)))
+  )
+
+(defmacro with-parsed-arguments (specs &rest forms)
+  "Execute FORMS with variable bindings according to SPECS.
+SPECS is structured as follows:
+SPECS   ::= (BINDING*)
+BINDING ::= (VAR TYPE)
+VAR is a symbol and TYPE is one of number, color, document-id and
+coding-system."
+  (declare (indent 1)
+	   (debug (listp &rest form)))
+  (let ((bindings
+	 (mapcar
+	  (lambda (spec)
+	    (destructuring-bind (var type) spec
+	      (list var
+		    (case type
+		      ;; Number
+		      (number
+		       `(string-to-number ,var 16))
+		      ;; Color
+		      (color
+		       `(rudel-obby-parse-color ,var))
+		      ;; Document Id
+		      (document-id
+		       `(mapcar
+			 (lambda (string)
+			   (string-to-number string 16))
+			 (split-string ,var " " t)))
+		      ;; Coding System
+		      (coding-system
+		       `(rudel-get-coding-system (downcase ,var)))))))
+	  specs)))
+    `(let (,@bindings)
+       ,@forms))
+  )
+
+(provide 'rudel-obby-util)
+;;; rudel-obby-util.el ends here
diff --git a/emacs.d/lisp/rudel/obby/.svn/text-base/rudel-obby.el.svn-base b/emacs.d/lisp/rudel/obby/.svn/text-base/rudel-obby.el.svn-base
new file mode 100644
index 0000000..a09c0d3
--- /dev/null
+++ b/emacs.d/lisp/rudel/obby/.svn/text-base/rudel-obby.el.svn-base
@@ -0,0 +1,488 @@
+;;; rudel-obby.el --- An obby backend for Rudel
+;;
+;; Copyright (C) 2008, 2009 Jan Moringen
+;;
+;; Author: Jan Moringen <scymtym@users.sourceforge.net>
+;; Keywords: Rudel, obby, backend, implementation
+;; X-RCS: $Id:$
+;;
+;; This file is part of Rudel.
+;;
+;; Rudel is free software: you can redistribute it and/or modify it
+;; under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+;;
+;; Rudel is distributed in the hope that it will be useful, but
+;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+;; General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with Rudel. If not, see <http://www.gnu.org/licenses>.
+
+
+;;; Commentary:
+;;
+;; This file contains a Rudel protocol backend, which implements the
+;; obby protocol (used by the Gobby collaborative editor until version
+;; 0.5).
+
+
+;;; History:
+;;
+;; 0.2 - Refactored client and server to employ state machine.
+;;
+;; 0.1 - Initial revision.
+
+
+;;; Code:
+;;
+
+(eval-when-compile
+  (require 'cl))
+
+(require 'eieio)
+
+(require 'rudel)
+(require 'rudel-backend)
+(require 'rudel-protocol)
+(require 'rudel-util)
+(require 'rudel-icons)
+(require 'rudel-compat) ;; for `read-color' replacement
+
+
+;;; Constants
+;;
+
+(defconst rudel-obby-version '(0 2)
+  "Version of the obby backend for Rudel.")
+
+(defconst rudel-obby-protocol-version 8
+  "Version of the obby protocol this library understands.")
+
+(defvar rudel-obby-long-message-threshold 32768
+  "Threshold for message size, above which messages are sent in
+multiple chunks.")
+
+(defvar rudel-obby-long-message-chunk-size 16384
+  "Chunk size used, when chunking long messages.")
+
+
+;;; Class rudel-obby-backend
+;;
+
+;;;###autoload
+(defclass rudel-obby-backend (rudel-protocol-backend)
+  ((capabilities :initform '(join host
+			     change-color
+			     track-subscriptions)))
+  "Main class of the Rudel obby backend. Creates obby client
+connections and creates obby servers.")
+
+(defmethod initialize-instance ((this rudel-obby-backend) &rest slots)
+  "Initialize slots of THIS with SLOTS."
+  (when (next-method-p)
+    (call-next-method))
+
+  (oset this :version rudel-obby-version))
+
+(defmethod rudel-ask-connect-info ((this rudel-obby-backend) &optional info)
+  "Ask user for the information required to connect to an obby server."
+  ;; Read server host and port.
+  (let ((host            (or (and info (plist-get info :host))
+			     (read-string "Server: ")))
+	(port            (or (and info (plist-get info :port))
+			     (read-number "Port: " 6522)))
+	;; Read desired username and color
+	(username        (or (and info (plist-get info :username))
+			     (read-string "Username: " user-login-name)))
+	(color           (or (and info (plist-get info :color))
+			     (read-color  "Color: " t)))
+	(encryption      (if (and info (member :encryption info))
+			     (plist-get info :encryption)
+			   (y-or-n-p "Use encryption? ")))
+	(global-password (if (and info (member :global-password info))
+			     (plist-get info :global-password)
+			   (read-string "Global password: " "")))
+	(user-password   (if (and info (member :user-password info))
+			     (plist-get info :user-password)
+			   (read-string "User password: " ""))))
+    (append (list :host            host
+		  :port            port
+		  :username        username
+		  :color           color
+		  :encryption      encryption
+		  :global-password (unless (string= global-password "")
+				     global-password)
+		  :user-password   (unless (string= user-password "")
+				     user-password))
+	    info))
+  )
+
+(defmethod rudel-connect ((this rudel-obby-backend) info)
+  "Connect to an obby server using the information INFO.
+Return the connection object."
+  ;; Before we start, load the client functionality.
+  (require 'rudel-obby-client)
+
+  ;; Create the network process
+  (let* ((session    (plist-get info :session))
+	 (host       (plist-get info :host))
+	 (port       (plist-get info :port))
+	 (encryption (plist-get info :encryption))
+	 ;; Create the network process
+	 (socket     (funcall
+		      (if encryption
+			  (progn
+			    (require 'rudel-tls)
+			    #'rudel-tls-make-process)
+			#'make-network-process)
+		      :name     host
+		      :host     host
+		      :service  port
+		      ;; Install connection filter to redirect data to
+		      ;; the connection object
+		      :filter   #'rudel-filter-dispatch
+		      ;; Install connection sentinel to redirect state
+		      ;; changes to the connection object
+		      :sentinel #'rudel-sentinel-dispatch
+		      ;; Do not start receiving immediately since the
+		      ;; filter function is not yet setup properly.
+		      :stop     t))
+	 (connection (rudel-obby-connection
+		      host
+		      :session session
+		      :socket  socket
+		      :info    info)))
+
+    ;; Now start receiving and wait until the basic session setup is
+    ;; complete.
+    (continue-process socket)
+
+    ;; Wait for the connection to reach one of the states idle,
+    ;; join-failed and they-finalized.
+    (condition-case error
+	(lexical-let ((reporter (make-progress-reporter "Joining ")))
+	  (flet ((display-progress (state)
+	           (cond
+		    ;; For all states, just spin.
+		    ((consp state)
+		     (progress-reporter-force-update
+                      reporter nil (format "Joining (%s)" (car state))))
+
+		    ;; Done
+		    (t
+		     (progress-reporter-force-update reporter nil "Joining ")
+		     (progress-reporter-done reporter)))))
+
+	    (rudel-state-wait connection
+			      '(idle) '(join-failed they-finalized)
+			      #'display-progress)))
+
+      (rudel-entered-error-state
+       (destructuring-bind (symbol . state) (cdr error)
+	 (if (eq (rudel-find-state connection 'join-failed) state)
+	     (with-slots (error-symbol error-data) state
+	       (signal 'rudel-join-error
+		       (append (list error-symbol) error-data)))
+	   (signal 'rudel-join-error nil)))))
+
+    ;; The connection is now usable; return it.
+    connection)
+  )
+
+(defmethod rudel-ask-host-info ((this rudel-obby-backend))
+  "Ask user for information required to host an obby session."
+  (let ((port (read-number "Port: " 6522)))
+    (list :port port)))
+
+(defmethod rudel-host ((this rudel-obby-backend) info)
+  "Host an obby session using the information INFO.
+Return the created server."
+  ;; Before we start, we load the server functionality.
+  (require 'rudel-obby-server)
+
+  ;; Create the network process.
+  (let* ((port   (plist-get info :port))
+	 ;; Make a server socket
+	 (socket (make-network-process
+		  :name     "obby-server"
+		  :host     "0.0.0.0"
+		  :service  port
+		  :server   t
+		  :filter   #'rudel-filter-dispatch
+		  :sentinel #'rudel-sentinel-dispatch
+		  ;;
+		  :log
+		  (lambda (server-process client-process message)
+		    (let ((server (rudel-process-object server-process)))
+		      (rudel-add-client server client-process)))))
+	 ;; Construct server object.
+	 (server (rudel-obby-server "obby-server"
+				    :backend this
+				    :socket  socket)))
+
+    ;; Return the constructed server.
+    server)
+  )
+
+(defmethod rudel-make-document ((this rudel-obby-backend)
+				name session)
+  "Make a new document in SESSION named NAME.
+Return the new document."
+  ;; Find an unused document id and create a document with that id.
+  (let ((id (rudel-available-document-id this session)))
+    (with-slots (user-id) (oref session :self)
+      (rudel-obby-document name
+			   :session  session
+			   :id       id
+			   :owner-id user-id
+			   :suffix   1)))
+  )
+
+(defmethod rudel-available-document-id ((this rudel-obby-backend)
+					session)
+  "Return a document id, which is not in use in SESSION."
+  ;; Look through some candidates until an unused id is hit.
+  (let* ((used-ids (with-slots (documents) session
+		     (mapcar 'rudel-id documents)))
+	 (test-ids (number-sequence 0 (length used-ids))))
+    (car (sort (set-difference test-ids used-ids) '<)))
+  )
+
+
+;;; Class rudel-obby-user
+;;
+
+(defclass rudel-obby-user (rudel-user)
+  ((client-id  :initarg  :client-id
+	       :type     (or null integer) ;; We allow nil instead of making
+	       :accessor rudel-client-id   ;; the slot unbound, to be able to
+	       :initform nil               ;; search with test `rudel-client-id
+	       :documentation              ;; without headaches
+	       "Id of the client connection, which the user used to log in.
+The value is an integer, if the user is connected, and nil
+otherwise.")
+   (user-id    :initarg  :user-id
+	       :type     integer
+	       :accessor rudel-id
+	       :documentation
+	       "")
+   (connected  :initarg  :connected
+	       :type     boolean
+	       :accessor rudel-connected
+	       :documentation
+	       "")
+   (encryption :initarg  :encryption ;; TODO maybe we should use unbound when the user is not connected
+	       :type     boolean
+	       :documentation
+	       ""))
+  "Class rudel-obby-user ")
+
+(defmethod eieio-speedbar-description ((this rudel-obby-user))
+  "Provide a speedbar description for THIS."
+  (let ((connected  (oref this :connected))
+	(encryption (if (slot-boundp this :encryption)
+			(oref this :encryption)
+		      nil)))
+    (format "User %s (%s, %s)" (object-name-string this)
+	    (if connected  "Online" "Offline")
+	    (if encryption "Encryption" "Plain")))
+  )
+
+(defmethod eieio-speedbar-object-buttonname ((this rudel-obby-user))
+  "Return a string to use as a speedbar button for THIS."
+  (rudel-display-string this))
+
+(defmethod rudel-display-string ((this rudel-obby-user)
+				 &optional use-images align)
+  "Return a textual representation of THIS for user interface stuff."
+  (with-slots (connected color) this
+    (let ((encryption  (and (slot-boundp this :encryption)
+			    (oref this :encryption)))
+	  (name-string (call-next-method)))
+      (concat
+       ;; Name bit
+       (cond
+	((numberp align) (format (format "%-%ds" align) name-string))
+	((eq align t)    (format "%-12s" name-string))
+	(t		name-string))
+
+       ;; Connection status bit
+       (apply
+	#'propertize
+	(if connected "c" "-")
+	'help-echo (format (if connected
+			       "%s is connected"
+			     "%s is not connected")
+			   name-string)
+	'face      (list :background color)
+	(when use-images
+	  (list 'display (if connected
+			     rudel-icon-connected
+			   rudel-icon-disconnected))))
+
+       ;; Encryption bit
+       (apply
+	#'propertize
+	(if encryption "e" "-")
+	'help-echo (format (if encryption
+			       "%s's connection is encrypted"
+			     "%s's connection is not encrypted")
+			   name-string)
+	'face      (list :background color)
+	(when use-images
+	  (list 'display (if encryption
+			     rudel-icon-encrypted
+			   rudel-icon-plaintext)))))))
+  )
+
+
+;;; Class rudel-obby-document
+;;
+
+(defclass rudel-obby-document (rudel-document)
+  ((id       :initarg  :id
+	     :type     integer
+	     :accessor rudel-id
+	     :documentation
+	     "The id of this document.
+The id has to be unique only with respect to the other documents
+owned by the owner.")
+   (owner-id :initarg  :owner-id
+	     :type     integer
+	     :documentation
+	     "")
+   (suffix   :initarg  :suffix
+	     :type     integer
+	     :documentation
+	     "A counter used to distinguish identically named
+documents."))
+  "Objects of the class rudel-obby-document represent shared
+documents in obby sessions.")
+
+(defmethod rudel-both-ids ((this rudel-obby-document))
+  "Return a list consisting of document and owner id of THIS document."
+  (with-slots ((doc-id :id) owner-id) this
+    (list owner-id doc-id)))
+
+(defmethod rudel-unique-name ((this rudel-obby-document))
+  "Generate a unique name for THIS based on the name and the suffix."
+  (with-slots (suffix) this
+    (concat (when (next-method-p)
+	      (call-next-method))
+	    (when (> suffix 1)
+	      (format "<%d>" suffix))))
+  )
+
+(defmethod eieio-speedbar-description ((this rudel-obby-document))
+  "Construct a description for from the name of document object THIS."
+  (format "Document %s" (object-name-string this)))
+
+(defmethod eieio-speedbar-object-buttonname ((this rudel-obby-document))
+  "Return a string to use as a speedbar button for OBJECT."
+  (with-slots (subscribed) this
+    (format "%-12s %s" (object-name-string this)
+	    (if subscribed "s" "-")))
+  )
+
+
+;;; Obby message functions
+;;
+
+(defun rudel-obby-replace-in-string (string replacements)
+  "Replace elements of REPLACEMENTS in STRING.
+REPLACEMENTS is a list of conses whose car is the pattern and
+whose cdr is the replacement for the pattern."
+  (let ((result string))
+    (dolist (replacement replacements)
+      (let ((from (car replacement))
+	    (to   (cdr replacement)))
+	(setq result (replace-regexp-in-string
+		      from to result nil t))))
+    result)
+  )
+
+(defun rudel-obby-escape-string (string)
+  "Replace meta characters in STRING with their escape sequences."
+  (rudel-obby-replace-in-string
+   string
+   '(("\\\\" . "\\b") ("\n" . "\\n") (":" . "\\d")))
+  )
+
+(defun rudel-obby-unescape-string (string)
+  "Replace escaped versions of obby meta characters in STRING with the actual meta characters."
+  (rudel-obby-replace-in-string
+   string
+   '(("\\\\n" . "\n") ("\\\\d" . ":") ("\\\\b" . "\\")))
+  )
+
+(defun rudel-obby-parse-color (color)
+  "Parse the obby color string COLOR into an Emacs color."
+  (let* ((color-numeric (string-to-number color 16))
+	 (color-string  (format "#%04X%04X%04X"
+				(lsh (logand #xff0000 color-numeric) -08)
+				(lsh (logand #x00ff00 color-numeric) -00)
+				(lsh (logand #x0000ff color-numeric)  08))))
+    color-string)
+  )
+
+(defun rudel-obby-format-color (color)
+  "Format the Emacs color COLOR as obby color string."
+  (multiple-value-bind (red green blue) (color-values color)
+    (format "%02x%02x%02x" (lsh red -8) (lsh green -8) (lsh blue -8))))
+
+(defun rudel-obby-assemble-message (name &rest arguments)
+  ""
+  (concat (mapconcat
+	   (lambda (part)
+	     (if (and (not (null part)) (stringp part))
+		 (rudel-obby-escape-string part)
+	       part))
+	   (cons name arguments) ":")
+	  "\n")
+  )
+
+(defun rudel-obby-parse-message (message)
+  "Split MESSAGE at `:' and unescape resulting parts.
+
+The terminating `\n' should be removed from MESSAGE before
+calling this function."
+  (mapcar #'rudel-obby-unescape-string (split-string message ":")))
+
+(defun rudel-obby-send (socket name arguments)
+  "Send an obby message NAME with arguments ARGUMENTS through SOCKET."
+  ;; First, assemble the message string.
+  (let ((message (apply #'rudel-obby-assemble-message
+			name arguments)))
+    (if (>= (length message) rudel-obby-long-message-threshold)
+	;; For huge messages, chunk the message data and transmit the
+	;; chunks
+	(let ((total    (/ (length message)
+			   rudel-obby-long-message-chunk-size))
+	      (current  0)
+	      (reporter (make-progress-reporter "Sending data " 0.0 1.0)))
+	  (rudel-loop-chunks message chunk rudel-obby-long-message-chunk-size
+	    (progress-reporter-update reporter (/ (float current) total))
+	    (process-send-string socket chunk)
+	    (incf current))
+	  (progress-reporter-done reporter))
+      ;; Send small messages in one chunk
+      (process-send-string socket message)))
+  )
+
+
+;;; Autoloading
+;;
+
+;;;###autoload
+(rudel-add-backend (rudel-backend-get-factory 'protocol)
+		   'obby 'rudel-obby-backend)
+
+;;;###autoload
+(eval-after-load 'rudel-zeroconf
+  '(rudel-zeroconf-register-service "_lobby._tcp" 'obby))
+
+(provide 'rudel-obby)
+;;; rudel-obby.el ends here
diff --git a/emacs.d/lisp/rudel/obby/Project.ede b/emacs.d/lisp/rudel/obby/Project.ede
new file mode 100644
index 0000000..53d2422
--- /dev/null
+++ b/emacs.d/lisp/rudel/obby/Project.ede
@@ -0,0 +1,14 @@
+;; Object rudel/obby
+;; EDE project file.
+(ede-proj-project "rudel/obby"
+  :name "obby"
+  :file "Project.ede"
+  :targets (list 
+   (ede-proj-target-elisp "obby"
+    :name "obby"
+    :path ""
+    :source '("rudel-obby.el" "rudel-obby-util.el" "rudel-obby-client.el" "rudel-obby-server.el" "rudel-obby-errors.el" "rudel-obby-state.el")
+    :aux-packages '("rudel" "jupiter")
+    )
+   )
+  )
diff --git a/emacs.d/lisp/rudel/obby/rudel-obby-client.el b/emacs.d/lisp/rudel/obby/rudel-obby-client.el
new file mode 100644
index 0000000..5c192db
--- /dev/null
+++ b/emacs.d/lisp/rudel/obby/rudel-obby-client.el
@@ -0,0 +1,973 @@
+;;; rudel-obby-client.el --- Client functions of the Rudel obby backend
+;;
+;; Copyright (C) 2008, 2009 Jan Moringen
+;;
+;; Author: Jan Moringen <scymtym@users.sourceforge.net>
+;; Keywords: Rudel, obby, backend, client
+;; X-RCS: $Id:$
+;;
+;; This file is part of Rudel.
+;;
+;; Rudel is free software: you can redistribute it and/or modify it
+;; under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+;;
+;; Rudel is distributed in the hope that it will be useful, but
+;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+;; General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with Rudel. If not, see <http://www.gnu.org/licenses>.
+
+
+;;; Commentary:
+;;
+;; This file contains the client part of the obby backend.
+
+
+;;; History:
+;;
+;; 0.2 - State machine.
+;;
+;; 0.1 - Initial revision.
+
+
+;;; Code:
+;;
+
+(require 'eieio)
+
+(require 'jupiter)
+
+(require 'rudel-state-machine)
+(require 'rudel-operations)
+(require 'rudel-chat)
+
+(require 'rudel-obby-errors)
+(require 'rudel-obby-util)
+(require 'rudel-obby-state)
+
+
+;;; Class rudel-obby-client-state-new
+;;
+
+(defclass rudel-obby-client-state-new
+  (rudel-obby-client-connection-state)
+  ()
+  "Start state of newly established connections.")
+
+(defmethod rudel-obby/obby_welcome
+  ((this rudel-obby-client-state-new) version)
+  "Handle obby 'welcome' message."
+  ;; Examine announced protocol version.
+  (with-parsed-arguments ((version number))
+    (message "Received Obby welcome message (version %d)" version))
+  ;; Start encryption handshake
+  'encryption-negotiate)
+
+
+;;; Class rudel-obby-client-state-encryption-negotiate
+;;
+
+(defclass rudel-obby-client-state-encryption-negotiate
+  (rudel-obby-client-connection-state)
+  ()
+  "Start state of the encryption handshake.")
+
+(defmethod rudel-obby/net6_encryption
+  ((this rudel-obby-client-state-encryption-negotiate) value)
+  "Handle net6 'encryption' message."
+  (rudel-send this "net6_encryption_ok")
+  'encryption-start)
+
+
+;;; Class rudel-obby-client-connection-encryption-start
+;;
+
+(defclass rudel-obby-client-state-encryption-start
+  (rudel-obby-client-connection-state)
+  ()
+  "Second state of the encryption handshake.")
+
+(defmethod rudel-obby/net6_encryption_begin
+  ((this rudel-obby-client-state-encryption-start))
+  "Handle net6 'encryption_begin' message."
+  ;; Start TLS encryption for the connection.
+  (with-slots (connection) this
+    (with-slots (socket) connection
+      (when (rudel-process-object socket :supports-tls)
+	(rudel-tls-start-tls socket)
+	(sit-for 1))))
+
+  ;; The connection is now established
+  'joining)
+
+(defmethod rudel-obby/net6_encryption_failed
+  ((this rudel-obby-client-state-encryption-start))
+  "Handle net6 'encryption_failed' message."
+  ;; The connection is now established; without encryption though
+  'joining)
+
+
+;;; Class rudel-obby-client-state-joining
+;;
+
+(defclass rudel-obby-client-state-joining
+  (rudel-obby-client-connection-state)
+  ()
+  "First state after the connection has been properly set up.")
+
+(defmethod rudel-enter ((this rudel-obby-client-state-joining))
+  "When entering this state, send a login request."
+  ;; Send login request with username and color. This can easily fail
+  ;; (resulting in response 'net6_login_failed') if the username or
+  ;; color is already taken.
+  (with-slots (info) (oref this connection)
+    (let ((username        (plist-get info :username))
+	  (color           (plist-get info :color))
+	  (global-password (plist-get info :global-password))
+	  (user-password   (plist-get info :user-password)))
+      (apply #'rudel-send
+	     this
+	     "net6_client_login"
+	     username (rudel-obby-format-color color)
+	     (append (when global-password
+		       (list global-password))
+		     (when (and global-password user-password)
+		       (list user-password))))))
+  nil)
+
+(defmethod rudel-obby/obby_sync_init
+  ((this rudel-obby-client-state-joining) count)
+  "Handle obby 'sync_init' message."
+  ;; Switch to 'synching' state, passing the number of synchronization
+  ;; items.
+  (with-parsed-arguments ((count number))
+    (list 'session-synching count)))
+
+(defmethod rudel-obby/net6_login_failed
+  ((this rudel-obby-client-state-joining) reason)
+  "Handle net6 'login_failed' message."
+  (with-parsed-arguments ((reason number))
+    (with-slots (connection) this
+      (let ((error-data
+	     (cond
+	      ;; Invalid username
+	      ((= reason rudel-obby-error-username-invalid)
+	       (cons 'rudel-obby-username-invalid nil))
+	      ;; Username in use
+	      ((= reason rudel-obby-error-username-in-use)
+	       (cons 'rudel-obby-username-in-use nil))
+	      ;; Color in use
+	      ((= reason rudel-obby-error-color-in-use)
+	       (cons 'rudel-obby-color-in-use nil))
+	      ;; Wrong global password
+	      ((= reason rudel-obby-error-wrong-global-password)
+	       (cons 'rudel-obby-wrong-global-password nil))
+	      ;; Wrong user password
+	      ((= reason rudel-obby-error-wrong-user-password)
+	       (cons 'rudel-obby-wrong-user-password nil))
+	      ;; Otherwise, signal a generic join error
+	      (t (cons 'rudel-join-error nil)))))
+
+	;; Switch to 'join-failed' state, pass the error data.
+	(list 'join-failed error-data))))
+  )
+
+
+;;; Class rudel-obby-client-state-join-failed
+;;
+
+(defclass rudel-obby-client-state-join-failed
+  (rudel-obby-client-connection-state)
+  ((error-symbol :initarg :error-symbol
+		 :type    symbol
+		 :documentation
+		 "Error symbol describing the reason for the
+login failure.")
+   (error-data   :initarg :error-data
+		 :type    list
+		 :documentation
+		 "Additional error data describing the login
+failure."))
+  "State for failed login attempts.")
+
+(defmethod rudel-enter ((this rudel-obby-client-state-join-failed)
+			error)
+  "When the state is entered, store the error data passed in ERROR."
+  (with-slots (error-symbol error-data) this
+    (setq error-symbol (car error)
+	  error-data   (cdr error)))
+  nil)
+
+
+;;; Class rudel-obby-client-state idle
+;;
+
+(defclass rudel-obby-client-state-idle
+  (rudel-obby-client-connection-state
+   rudel-obby-document-handler)
+  ()
+  "Default state of the connection.")
+
+(defmethod rudel-obby/net6_client_join
+  ((this rudel-obby-client-state-idle)
+   client-id name encryption user-id color)
+  "Handle net6 'client_join' message."
+  (with-parsed-arguments ((client-id number)
+			  (user-id   number)
+			  (color     color))
+    (with-slots (connection) this
+      (with-slots (session) connection
+	(let ((user (rudel-find-user session user-id
+				     #'eq #'rudel-id)))
+	  (if user
+	      ;; If we have such a user object, update its state.
+	      (with-slots ((client-id1  client-id)
+			   (color1      color)
+			   connected
+			   (encryption1 encryption)) user
+		(setq client-id1  client-id
+		      color1      color
+		      connected   t
+		      encryption1 (string= encryption "1"))
+
+		;; Run the change hook of the user object.
+		(object-run-hook-with-args user 'change-hook))
+	    ;; Otherwise, create a new user object.
+	    (let ((user (rudel-obby-user
+			 name
+			 :client-id  client-id
+			 :user-id    user-id
+			 :connected  t
+			 :encryption (string= encryption "1")
+			 :color      color)))
+	      (rudel-add-user session user))))))
+    (message "Client joined: %s %s" name color))
+  nil)
+
+(defmethod rudel-obby/net6_client_part
+  ((this rudel-obby-client-state-idle) client-id)
+  "Handle net6 'client_part' message."
+  ;; Find the user object, associated to the client id. Remove the
+  ;; client id and change the user's state to disconnected.
+  (with-parsed-arguments ((client-id number))
+    (with-slots (connection) this
+      (with-slots (session) connection
+	(let ((user (rudel-find-user session client-id
+				     #'eql #'rudel-client-id)))
+	  (if user
+	      (with-slots (client-id connected) user
+		;; Set slot values.
+		(setq client-id nil
+		      connected nil)
+
+		;; Run the change hook of the user object.
+		(object-run-hook-with-args user 'change-hook))
+	    (display-warning
+	     '(rudel obby)
+	     (format "Cannot find user for client id: %d"
+		     client-id)
+	     :warning))))))
+  nil)
+
+(defmethod rudel-obby/obby_user_colour
+  ((this rudel-obby-client-state-idle) user-id color)
+  "Handle obby 'user_colour' message."
+  (with-parsed-arguments ((user-id number)
+			  (color   color))
+    ;; Find user object and set color.
+    (with-slots (connection) this
+      (with-slots (session) connection
+	(let ((user (rudel-find-user session user-id
+				     #'= #'rudel-id)))
+	  (with-slots ((name :object-name) (color1 :color)) user
+	    ;; Set color in user object.
+	    (setq color1 color)
+
+	    ;; Run the change hook of the user object.
+	    (object-run-hook-with-args user 'change-hook)
+
+	    ;; Update overlays.
+	    (rudel-overlay-set-face-attributes
+	     (rudel-overlay-make-face-symbol 'author name)
+	     color1))))))
+  nil)
+
+(defmethod rudel-obby/obby_document_create
+  ((this rudel-obby-client-state-idle)
+   owner-id doc-id name suffix encoding)
+  "Handle obby 'document_create' message."
+  (with-parsed-arguments ((owner-id number)
+			  (doc-id   number)
+			  (suffix   number)
+			  (encoding coding-system))
+    (with-slots (connection) this
+      (with-slots (session) connection
+	(let ((owner (rudel-find-user session owner-id
+				      #'= #'rudel-id)))
+	  (rudel-add-document session (rudel-obby-document
+				       name
+				       :subscribed (list owner)
+				       :id         doc-id
+				       :owner-id   owner-id
+				       :suffix     suffix))))
+      (message "New document: %s" name)))
+  nil)
+
+(defmethod rudel-obby/obby_document_remove
+  ((this rudel-obby-client-state-idle) doc-id)
+  "Handle obby 'document_remove' message."
+  (with-parsed-arguments ((doc-id document-id))
+    (with-slots (connection) this
+      (with-slots (session) connection
+	(let ((document (rudel-find-document
+			 session doc-id
+			 #'equal #'rudel-both-ids)))
+	  (if document
+	      (progn
+		(rudel-remove-document session document)
+		(with-slots ((name :object-name)) document
+		  (message "Document removed: %s" name)))
+	    (display-warning
+	     '(rudel obby)
+	     (format "Document not found: %s" doc-id)
+	     :warning))))))
+  nil)
+
+(defmethod rudel-obby/obby_document/rename
+  ((this rudel-obby-client-state-idle)
+   document user new-name new-suffix)
+  "Handle obby 'rename' submessage of the 'obby_document' message."
+  (with-parsed-arguments ((new-suffix number))
+    (with-slots ((name :object-name) suffix) document
+      (setq name   new-name
+	    suffix new-suffix)))
+  nil)
+
+(defmethod rudel-obby/obby_document/subscribe
+  ((this rudel-obby-client-state-idle)
+   document user-id)
+  "Handle 'subscribe' submessage of obby 'document' message."
+  (with-parsed-arguments ((user-id number))
+    (with-slots (connection) this
+      (with-slots (session) connection
+	(let ((user (rudel-find-user session user-id
+				     #'= #'rudel-id)))
+	  (rudel-add-user document user)))))
+  nil)
+
+(defmethod rudel-obby/obby_document/unsubscribe
+  ((this rudel-obby-client-state-idle)
+   document user-id)
+  "Handle 'unsubscribe' submessage of obby 'document' message."
+  (with-parsed-arguments ((user-id number))
+    (with-slots (connection) this
+      (with-slots (session) connection
+	(let ((user (rudel-find-user session user-id
+				     #'= #'rudel-id)))
+	  (rudel-remove-user document user)))))
+  nil)
+
+(defmethod rudel-obby/obby_document/record
+  ((this rudel-obby-client-state-idle)
+   document user-id local-revision remote-revision
+   action &rest arguments)
+  "Handle 'record' submessage of obby 'document' message."
+  (with-parsed-arguments ((user-id         number)
+			  (local-revision  number)
+			  (remote-revision number))
+    ;; Locate the user.
+    (let ((user (with-slots (connection) this
+		  (with-slots (session) connection
+		    (rudel-find-user session user-id
+				     #'= #'rudel-id)))))
+      (if user
+	  (condition-case error
+	      ;; Try to dispatch
+	      (rudel-dispatch
+	       this "rudel-obby/obby_document/record/" action
+	       (append (list document user local-revision remote-revision)
+		       arguments))
+	    ;; Warn if we failed to locate or execute the
+	    ;; method. Return nil in this case, so we remain in the
+	    ;; current state.
+	    (rudel-dispatch-error
+	     (progn
+	       (display-warning
+		'(rudel obby)
+		(format "%s: no method (%s: %s): `%s:%s'; arguments: %s"
+			(object-print this) (car error) (cdr error)
+			"rudel-obby/obby_document/record/" action arguments)
+		:debug)
+		nil)))
+	;; If we did not find the user, warn.
+	(progn
+	  (display-warning
+	   '(rudel obby)
+	   (format "User not found: %d" user-id)
+	   :warning)
+	  nil))))
+  )
+
+(defmethod rudel-obby/obby_document/record/ins
+  ((this rudel-obby-client-state-idle)
+   document user local-revision remote-revision
+   position data)
+  "Handle 'ins' submessage of 'record' submessage of obby 'document' message."
+  (with-parsed-arguments ((position number))
+    (let ((operation (jupiter-insert
+		      (format "insert-%d-%d"
+			      remote-revision local-revision)
+		      :from position
+		      :data data)))
+      (with-slots (connection) this
+	(rudel-remote-operation connection
+				document user
+				remote-revision local-revision
+				operation))))
+  nil)
+
+(defmethod rudel-obby/obby_document/record/del
+  ((this rudel-obby-client-state-idle)
+   document user local-revision remote-revision
+   position length)
+  "Handle 'del' submessage of 'record' submessage of obby 'document' message."
+  (with-parsed-arguments ((position number)
+			  (length   number))
+    (let ((operation (jupiter-delete
+		      (format "delete-%d-%d"
+			      remote-revision local-revision)
+		      :from position
+		      :to   (+ position length))))
+      (with-slots (connection) this
+	(rudel-remote-operation connection
+				document user
+				remote-revision local-revision
+				operation))))
+  nil)
+
+(defmethod rudel-obby/obby_document/record/split
+  ((this rudel-obby-client-state-idle)
+   document user local-revision remote-revision
+   &rest operations)
+  "Handle 'split' submessage of 'record' submessage of obby 'document' message."
+  (let ((operation (rudel-message->operation
+		    (cons "split" operations)
+		    local-revision remote-revision)))
+    (with-slots (connection) this
+      (rudel-remote-operation connection
+			      document user
+			      remote-revision local-revision
+			      operation)))
+  nil)
+
+(defmethod rudel-obby/obby_document/record/noop
+  ((this rudel-obby-client-state-idle)
+   document user local-revision remote-revision)
+  "Handle 'noop' submessage of 'record' submessage of obby 'document' message."
+  (let ((operation (jupiter-nop
+		    (format "nop-%d-%d"
+			    remote-revision local-revision))))
+    (with-slots (connection) this
+      (rudel-remote-operation connection
+			      document user
+			      remote-revision local-revision
+			      operation)))
+  nil)
+
+(defmethod rudel-obby/obby_message ((this rudel-obby-client-state-idle)
+				    sender text)
+  "Handle obby 'message' message"
+  (with-parsed-arguments ((sender number))
+    (with-slots (session) (oref this :connection)
+      (let ((sender (rudel-find-user session sender #'eq #'rudel-id)))
+	(rudel-chat-dispatch-message sender text))))
+  nil)
+
+
+;;; Class rudel-obby-client-state-session-synching
+;;
+
+(defclass rudel-obby-client-state-session-synching
+  (rudel-obby-client-connection-state)
+  ((all-items       :initarg  :all-items
+		    :type     (integer 0)
+		    :documentation
+		    "Total number of synchronization items expected
+		    to receive from the server.")
+   (remaining-items :initarg  :remaining-items
+		    :type     (integer 0)
+		    :documentation
+		    "Number of synchronization items not yet
+		    received from the server.")
+   (have-self       :initarg  :have-self
+		    :type     boolean
+		    :documentation
+		    "Flag that remembers, whether the session has
+		    a 'self' user object."))
+  "State used for synching session data.")
+
+(defmethod rudel-enter ((this rudel-obby-client-state-session-synching)
+			num-items)
+  "When entering state, store number of expected items."
+  (with-slots (all-items remaining-items have-self) this
+    (setq all-items       num-items
+	  remaining-items num-items
+	  have-self       nil))
+  nil)
+
+(defmethod rudel-obby/net6_client_join
+  ((this rudel-obby-client-state-session-synching)
+   client-id name encryption user-id color)
+  "Handle net6 'client_join' message."
+  (with-parsed-arguments ((client-id number)
+			  (user-id   number)
+			  (color     color))
+    (with-slots (connection remaining-items have-self) this
+      (with-slots (session) connection
+	;; Construct user object and add it to the session.
+	(let ((user (rudel-obby-user
+		     name
+		     :client-id  client-id
+		     :user-id    user-id
+		     :connected  t
+		     :encryption (string= encryption "1")
+		     :color      color)))
+	  (rudel-add-user session user)
+
+	  ;; The first user object describes the user of this client.
+	  (unless have-self
+	    (with-slots (self) session
+	      (setq self      user
+		    have-self t)))))
+
+      ;; Decrease number of not yet received synchronization items.
+      (decf remaining-items)))
+  nil)
+
+(defmethod rudel-obby/obby_sync_usertable_user
+  ((this rudel-obby-client-state-session-synching) user-id name color)
+  "Handle obby 'sync_usertable_user' message."
+  (with-parsed-arguments ((user-id number)
+			  (color   color))
+    (with-slots (connection remaining-items) this
+      (with-slots (session) connection
+	(rudel-add-user session (rudel-obby-user
+				 name
+				 :user-id    user-id
+				 :connected  nil
+				 :color      color)))
+
+      ;; Decrease number of not yet received synchronization items.
+      (decf remaining-items)))
+  nil)
+
+(defmethod rudel-obby/obby_sync_doclist_document
+  ((this rudel-obby-client-state-session-synching)
+   owner-id doc-id name suffix encoding &rest subscribed-user-ids)
+  "Handle obby 'sync_doclist_document' message."
+  (with-parsed-arguments ((doc-id   number)
+			  (owner-id number)
+			  (suffix   number)
+			  (encoding coding-system))
+    (with-slots (connection remaining-items) this
+      (with-slots (session) connection
+	;; Retrieve the subscribed users
+	(let ((subscribed-users
+	       (mapcar
+		(lambda (user-id)
+		  (with-parsed-arguments ((user-id number))
+		    (rudel-find-user session user-id
+				     #'= #'rudel-id)))
+		subscribed-user-ids)))
+
+	  ;; Make a new document with the list of subscribed users.
+	  (rudel-add-document session (rudel-obby-document
+				       name
+				       :subscribed subscribed-users
+				       :id         doc-id
+				       :owner-id   owner-id
+				       :suffix     suffix))))
+
+      ;; Decrease number of not yet received synchronization items.
+      (decf remaining-items)))
+  nil)
+
+(defmethod rudel-obby/obby_sync_final
+  ((this rudel-obby-client-state-session-synching))
+  "Handle obby 'sync_final' message."
+  'idle)
+
+(defmethod object-print ((this rudel-obby-client-state-session-synching)
+			 &rest strings)
+  "Append number of remaining items to string representation."
+  (with-slots (remaining-items) this
+    (call-next-method this (format " remaining: %d" remaining-items))))
+
+
+;;; Class rudel-obby-client-state-subscribing
+;;
+
+(defclass rudel-obby-client-state-subscribing
+  (rudel-obby-client-connection-state
+   rudel-obby-document-handler)
+  ((document :initarg :document
+	     :type    rudel-obby-document-child
+	     :documentation
+	     ""))
+  "")
+
+(defmethod rudel-enter ((this rudel-obby-client-state-subscribing)
+			user document)
+  "When entering this state, send a subscription request to the server."
+  (with-slots ((document1 :document)) this
+    (setq document1 document)
+
+    (with-slots ((doc-id :id) owner-id) document1
+      (with-slots (user-id) user
+	(rudel-send this "obby_document"
+		    (format "%x %x" owner-id doc-id)
+		    "subscribe"
+		    (format "%x" user-id)))))
+  nil)
+
+(defmethod rudel-obby/obby_document/sync_init
+  ((this rudel-obby-client-state-subscribing)
+   document num-bytes)
+  "Handle obby 'sync_init' message."
+  (with-parsed-arguments ((num-bytes number))
+    (with-slots (documents) this
+      (if (= num-bytes 0)
+	  'idle
+	(list 'document-synching document num-bytes))))
+  )
+
+
+;;; Class rudel-obby-client-state-document-synching
+;;
+
+(defclass rudel-obby-client-state-document-synching
+  (rudel-obby-client-connection-state
+   rudel-obby-document-handler)
+  ((document        :initarg  :document
+		    :type     rudel-obby-document-child
+		    :documentation
+		    "")
+   (all-bytes       :initarg  :all-bytes
+		    :type     (integer 0)
+		    :documentation
+		    "")
+   (remaining-bytes :initarg  :remaining-bytes
+		    :type     (integer 0)
+		    :documentation
+		    ""))
+  "")
+
+(defmethod rudel-enter ((this rudel-obby-client-state-document-synching)
+			document num-bytes)
+  ""
+  (with-slots ((document1 :document) all-bytes remaining-bytes) this
+    (setq document1       document
+	  all-bytes       num-bytes
+	  remaining-bytes num-bytes))
+  nil)
+
+(defmethod rudel-obby/obby_document/sync_chunk
+  ((this rudel-obby-client-state-document-synching)
+   document data user-id)
+  "Handle obby 'sync_chunk' message."
+  (with-parsed-arguments ((user-id number))
+    (with-slots (connection remaining-bytes) this
+      (with-slots (session) connection
+	(let* ((user      (unless (zerop user-id)
+			    (rudel-find-user session user-id
+					     #'= #'rudel-id)))
+	       (operation (rudel-insert-op "bulk-insert"
+					   :from nil
+					   :data data)))
+	  (rudel-remote-operation document user operation)))
+
+      ;; After all bytes are transferred, go back to idle state.
+      (decf remaining-bytes (string-bytes data))
+      (if (= remaining-bytes 0)
+	  'idle
+	nil)))
+  )
+
+(defmethod object-print ((this rudel-obby-client-state-document-synching)
+			 &rest strings)
+  "Append number of remaining items to string representation."
+  (with-slots (remaining-bytes) this
+    (call-next-method this (format " remaining: %d" remaining-bytes))))
+
+
+;;; Class rudel-obby-client-state-they-finalized
+;;
+
+(defclass rudel-obby-client-state-they-finalized
+  (rudel-obby-client-connection-state)
+  ()
+  "State used to indicate that the connection was closed by the peer.")
+
+
+;;; Client connection states.
+;;
+
+(defvar rudel-obby-client-connection-states
+  '((new                  . rudel-obby-client-state-new)
+    (encryption-negotiate . rudel-obby-client-state-encryption-negotiate)
+    (encryption-start     . rudel-obby-client-state-encryption-start)
+    (joining              . rudel-obby-client-state-joining)
+    (join-failed          . rudel-obby-client-state-join-failed)
+    (idle                 . rudel-obby-client-state-idle)
+    (session-synching     . rudel-obby-client-state-session-synching)
+    (subscribing          . rudel-obby-client-state-subscribing)
+    (document-synching    . rudel-obby-client-state-document-synching)
+    (they-finalized       . rudel-obby-client-state-they-finalized))
+  "Name symbols and classes of connection states.")
+
+
+;;; Class rudel-obby-connection
+;;
+
+(defclass rudel-obby-connection (rudel-obby-socket-owner
+				 rudel-connection
+				 rudel-state-machine)
+  ((info     :initarg :info
+	     :type    list
+	     :documentation
+	     "Stores connection information for later use.")
+   (contexts :initarg :contexts
+	     :type    hash-table
+	     :documentation
+	     "Contains jupiter context objects for all
+documents."))
+  "Class rudel-obby-connection ")
+
+(defmethod initialize-instance ((this rudel-obby-connection) &rest slots)
+  ;; Initialize slots of THIS
+  (when (next-method-p)
+    (call-next-method))
+
+  ;; Create a new hash-table object to hold jupiter contexts
+  ;; associated to documents.
+  (with-slots (contexts) this
+    (setq contexts (make-hash-table :test #'equal)))
+
+  ;; Register states.
+  (rudel-register-states this rudel-obby-client-connection-states)
+  )
+
+(defmethod rudel-register-state ((this rudel-obby-connection)
+				 symbol state)
+  "Register SYMBOL and STATE and set connection slot of STATE."
+  ;; Associate THIS connection to STATE.
+  (oset state :connection this)
+
+  ;; Register STATE.
+  (when (next-method-p)
+    (call-next-method))
+  )
+
+(defmethod rudel-disconnect ((this rudel-obby-connection))
+  ""
+  (when (next-method-p)
+    (call-next-method)))
+
+(defmethod rudel-close ((this rudel-obby-connection))
+  ""
+  ;; Move the state machine into an error state.
+  (rudel-switch this 'they-finalized)
+
+  ;; Terminate the session.
+  (with-slots (session) this
+    (rudel-end session)))
+
+(defmethod rudel-find-context ((this rudel-obby-connection) document)
+  "Return the jupiter context associated to DOCUMENT in THIS connection."
+  (with-slots (contexts) this
+    (gethash (oref document :id) contexts)))
+
+(defmethod rudel-add-context ((this rudel-obby-connection) document)
+  "Add a jupiter context for DOCUMENT to THIS connection."
+  (with-slots (contexts) this
+    (with-slots ((doc-name :object-name) (doc-id :id)) document
+      (puthash doc-id
+	       (jupiter-context (format "%s" doc-name))
+	       contexts)))
+  )
+
+(defmethod rudel-remove-context ((this rudel-obby-connection) document)
+  "Remove the jupiter context associated to DOCUMENT from THIS connection."
+  (with-slots (contexts) this
+    (remhash (oref document :id) contexts)))
+
+(defmethod rudel-message ((this rudel-obby-connection) message)
+  "Dispatch MESSAGE to the current state of THIS object.
+If the state has no suitable method, generate a warning, but do
+nothing else."
+  ;; Dispatch message to state.
+  (rudel-accept this message))
+
+(defmethod rudel-change-color- ((this rudel-obby-connection) color)
+  ""
+  (rudel-send this "obby_user_colour"
+	      (rudel-obby-format-color color)))
+
+(defmethod rudel-publish ((this rudel-obby-connection) document)
+  ""
+  ;; Create a new jupiter context for DOCUMENT.
+  (rudel-add-context this document)
+
+  ;; Announce the new document to the server.
+  (with-slots ((name :object-name) id buffer) document
+    (rudel-send this "obby_document_create"
+		(format "%x" id)
+		name
+		"UTF-8"
+		(with-current-buffer buffer
+		  (buffer-string))))
+  )
+
+(defmethod rudel-unpublish ((this rudel-obby-connection) document)
+  "Remove DOCUMENT from the obby session THIS is connected to."
+  ;; Request removal of DOCUMENT.
+  (with-slots ((doc-id :id) owner-id) document
+      (rudel-send this "obby_document_remove"
+		  (format "%x %x" owner-id doc-id)))
+
+  ;; Remove the jupiter context for DOCUMENT.
+  (rudel-remove-context this document)
+  )
+
+(defmethod rudel-subscribe-to ((this rudel-obby-connection) document)
+  ""
+  ;; Create a new jupiter context for DOCUMENT.
+  (rudel-add-context this document)
+
+  ;; Switch to subscribing state and wait until the state goes back to
+  ;; idle.
+  (with-slots (session) this
+    (with-slots (self) session
+      (rudel-switch this 'subscribing self document)))
+
+  (lexical-let ((reporter (make-progress-reporter "Subscribing " 0.0 1.0)))
+    (flet ((display-progress (state)
+	     (cond
+	      ;; Syncing document content, we can provide detailed progress.
+	      ((and (consp state)
+		    (eq (car state) 'document-synching))
+	       (with-slots (all-bytes remaining-bytes) (cdr state)
+		 (progress-reporter-force-update
+		  reporter
+		  (- 1.0 (/ (float remaining-bytes) (float all-bytes)))
+		  (format "Subscribing (%s) " (car state)))))
+
+	      ;; For other states, we just spin.
+	      ((consp state)
+	       (progress-reporter-force-update
+	        reporter 0.5
+	        (format "Subscribing (%s) " (car state))))
+
+	      ;; Done
+	      (t
+	       (progress-reporter-force-update reporter 1.0 "Subscribing ")
+	       (progress-reporter-done reporter)))))
+      (rudel-state-wait this '(idle) '(they-finalized) #'display-progress)))
+
+  ;; We receive a notification of our own subscription from the
+  ;; server. Consequently we do not add SELF to the list of subscribed
+  ;; users of DOCUMENT.
+  )
+
+(defmethod rudel-unsubscribe-from ((this rudel-obby-connection) document)
+  ""
+  ;; Delete the jupiter context for DOCUMENT.
+  (rudel-remove-context this document)
+
+  ;; Announce the end of our subscription to the server.
+  (with-slots (session) this
+    (with-slots (user-id) (oref session :self)
+      (with-slots ((doc-id :id) owner-id) document
+	(rudel-send this "obby_document"
+		    (format "%x %x" owner-id doc-id)
+		    "unsubscribe"
+		    (format "%x" user-id)))))
+
+  ;; We receive a notification of the end of our own subscription from
+  ;; the server. Consequently we do not remove SELF from the list of
+  ;; subscribed users of DOCUMENT.
+  )
+
+(defmethod rudel-local-insert ((this rudel-obby-connection)
+			       document position data)
+  ""
+  (rudel-local-operation
+   this
+   document
+   (jupiter-insert "insert" :from position :data data)))
+
+(defmethod rudel-local-delete ((this rudel-obby-connection)
+			       document position length)
+  ""
+  (rudel-local-operation
+   this
+   document
+   (jupiter-delete "delete" :from position :to (+ position length))))
+
+(defmethod rudel-local-operation ((this rudel-obby-connection)
+				  document operation)
+  "Handle OPERATION performed on DOCUMENT by sending a message through THIS connection."
+  ;; Convert character positions in OPERATION to byte positions, since
+  ;; the obby protocol works with byte positions, but Emacs uses
+  ;; character positions.
+  (with-slots (buffer) document
+    (rudel-obby-char->byte operation buffer))
+
+  ;; Find jupiter context for DOCUMENT.
+  (let ((context (rudel-find-context this document)))
+
+    ;; Notify the server of the operation.
+    (with-slots (owner-id (doc-id :id)) document
+      (with-slots (local-revision remote-revision) context
+	(apply #'rudel-send
+	       this
+	       "obby_document"
+	       (format "%x %x" owner-id doc-id)
+	       "record"
+	       (format "%x" local-revision)
+	       (format "%x" remote-revision)
+	       (rudel-operation->message operation))))
+
+      ;; Submit the operation to the jupiter context.
+      (jupiter-local-operation context operation))
+  )
+
+(defmethod rudel-remote-operation ((this rudel-obby-connection)
+				   document user
+				   remote-revision local-revision
+				   operation)
+  "Handle OPERATION received through THIS connection performed by USER on DOCUMENT."
+  (let* (;; Find jupiter context for DOCUMENT.
+	 (context     (rudel-find-context this document))
+	 ;; And transform the operation.
+	 (transformed (jupiter-remote-operation
+		       context
+		       remote-revision local-revision
+		       operation)))
+
+    ;; Convert byte positions in OPERATION to character positions,
+    ;; since the obby protocol works with byte positions, but Emacs
+    ;; uses character positions.
+    (with-slots (buffer) document
+      (rudel-obby-byte->char transformed buffer))  ;; TODO operation's responsibility?
+
+    ;; Apply the transformed operation to the document.
+    (rudel-remote-operation document user transformed))
+  )
+
+(provide 'rudel-obby-client)
+;;; rudel-obby-client.el ends here
diff --git a/emacs.d/lisp/rudel/obby/rudel-obby-debug.el b/emacs.d/lisp/rudel/obby/rudel-obby-debug.el
new file mode 100644
index 0000000..8f5f168
--- /dev/null
+++ b/emacs.d/lisp/rudel/obby/rudel-obby-debug.el
@@ -0,0 +1,122 @@
+;;; rudel-obby-debug.el --- Debugging functions for obby backend
+;;
+;; Copyright (C) 2009 Jan Moringen
+;;
+;; Author: Jan Moringen <scymtym@users.sourceforge.net>
+;; Keywords: Rudel, obby, debugging
+;; X-RCS: $Id:$
+;;
+;; This program is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+;;
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; GNU General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with this program. If not, see <http://www.gnu.org/licenses>.
+
+
+;;; Commentary:
+;;
+;; Debugging functions for the obby backend.
+
+
+;;; History:
+;;
+;; 0.1 - Initial revision.
+
+
+;;; Code:
+;;
+
+(require 'eieio)
+
+(require 'rudel-debug)
+
+(require 'rudel-obby-util)
+
+
+;;; Variables
+;;
+
+(defvar rudel-obby-debug-old-state nil
+  "Saves state of state machines across one function call.")
+
+
+;;; Functions
+;;
+
+(defmethod rudel-send :before ((this rudel-obby-socket-owner)
+			       name &rest arguments)
+  "Print NAME and ARGUMENTS to debug stream."
+  (let ((message (apply #'rudel-obby-assemble-message
+			name arguments)))
+
+    (with-slots (socket) this
+      (rudel-debug-stream-insert
+       (rudel-debug-stream-name socket)
+       :sent
+       (concat  (substring message 0 (min (length message) 100))
+		(when (> (length message) 100)
+		  "..."))
+       (append (list name) arguments))))
+    )
+
+(defmethod rudel-receive :before ((this rudel-obby-socket-owner) data)
+  "Print DATA to debug stream."
+  (with-slots (socket) this
+    (rudel-debug-stream-insert
+     (rudel-debug-stream-name socket)
+     :received
+     (concat (substring data 0 (min (length data) 100))
+	     (when (> (length data) 100)
+	       "..."))))
+  )
+
+(defmethod rudel-message :before ((this rudel-obby-socket-owner)
+				  message)
+  "Print DATA to debug stream."
+  (let ((data (apply #'rudel-obby-assemble-message message)))
+
+    (with-slots (socket) this
+      (rudel-debug-stream-insert
+       (rudel-debug-stream-name socket)
+       :received-processed
+       (concat (substring data 0 (min (length data) 100))
+	       (when (> (length data) 100)
+		 "..."))
+       message)
+      ))
+  )
+
+(defmethod rudel-switch :before ((this rudel-obby-socket-owner)
+				 state &rest arguments)
+  "Store name of STATE for later printing."
+  (with-slots (state) this
+    (setq rudel-obby-debug-old-state
+	  (if state
+	      (object-name-string state)
+	    "#start")))
+  )
+
+(defmethod rudel-switch :after ((this rudel-obby-socket-owner)
+				state &rest arguments)
+  "Print STATE and ARGUMENTS to debug stream."
+  (with-slots (socket state) this
+    (let ((old-state rudel-obby-debug-old-state)
+	  (new-state (object-name-string state)))
+      (unless (string= old-state new-state)
+	(rudel-debug-stream-insert
+	 (rudel-debug-stream-name socket)
+	 :special
+	 (if arguments
+	     (format "%s -> %s %s" old-state new-state arguments)
+	   (format "%s -> %s" old-state new-state))))))
+  )
+
+(provide 'rudel-obby-debug)
+;;; rudel-obby-debug.el ends here
diff --git a/emacs.d/lisp/rudel/obby/rudel-obby-errors.el b/emacs.d/lisp/rudel/obby/rudel-obby-errors.el
new file mode 100644
index 0000000..689d4a8
--- /dev/null
+++ b/emacs.d/lisp/rudel/obby/rudel-obby-errors.el
@@ -0,0 +1,65 @@
+;;; rudel-obby-errors.el --- Error data used in the obby Rudel backend
+;;
+;; Copyright (C) 2009 Jan Moringen
+;;
+;; Author: Jan Moringen <scymtym@users.sourceforge.net>
+;; Keywords: Rudel, obby, errors
+;; X-RCS: $Id:$
+;;
+;; This file is part of Rudel.
+;;
+;; Rudel is free software: you can redistribute it and/or modify it
+;; under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+;;
+;; Rudel is distributed in the hope that it will be useful, but
+;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+;; General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with Rudel. If not, see <http://www.gnu.org/licenses>.
+
+
+;;; Commentary:
+;;
+;; This file contains definitions of error conditions and numeric
+;; error codes used in the Rudel obby backend.
+
+
+;;; History:
+;;
+;; 0.1 - Initial revision.
+
+
+;;; Code:
+;;
+
+
+;;; Obby protocol error codes
+;;
+
+(defconst rudel-obby-error-username-invalid #x0001
+  "Error code for invalid username.")
+
+(defconst rudel-obby-error-username-in-use #x0002
+  "Error code for username already in use.")
+
+(defconst rudel-obby-error-color-in-use #x0100
+  "Error code for color already in use.")
+
+(defconst rudel-obby-error-wrong-global-password #x0101
+  "Error code for wrong global password.")
+
+(defconst rudel-obby-error-wrong-user-password #x0102
+  "Error code for wrong user password.")
+
+(defconst rudel-obby-error-protocol-version-mismatch #x0103
+  "Error code for protocol version mismatch.")
+
+(defconst rudel-obby-error-not-encrypted  #x0104
+  "Error code for not encrypted.")
+
+(provide 'rudel-obby-errors)
+;;; rudel-obby-errors.el ends here
diff --git a/emacs.d/lisp/rudel/obby/rudel-obby-server.el b/emacs.d/lisp/rudel/obby/rudel-obby-server.el
new file mode 100644
index 0000000..5bf1158
--- /dev/null
+++ b/emacs.d/lisp/rudel/obby/rudel-obby-server.el
@@ -0,0 +1,798 @@
+;;; rudel-obby-server.el --- Server component of the Rudel obby backend
+;;
+;; Copyright (C) 2008, 2009 Jan Moringen
+;;
+;; Author: Jan Moringen <scymtym@users.sourceforge.net>
+;; Keywords: Rudel, obby, backend, server
+;; X-RCS: $Id:$
+;;
+;; This file is part of Rudel.
+;;
+;; Rudel is free software: you can redistribute it and/or modify it
+;; under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+;;
+;; Rudel is distributed in the hope that it will be useful, but
+;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+;; General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with Rudel. If not, see <http://www.gnu.org/licenses>.
+
+
+;;; Commentary:
+;;
+;; This file contains the server part of the obby backend for Rudel.
+;;
+;; It is implemented using one state machine (class
+;; `rudel-obby-client') for each client connection. These state
+;; machines have the following states:
+;;
+;; + new                  `rudel-obby-server-state-new'
+;; + encryption-negotiate `rudel-obby-server-state-encryption-negotiate'
+;; + before-join          `rudel-obby-server-state-before-join'
+;; + idle                 `rudel-obby-server-state-idle'
+
+
+;;; History:
+;;
+;; 0.2 - State machine.
+;;
+;; 0.1 - Initial revision.
+
+
+;;; Code:
+;;
+
+(eval-when-compile
+  (require 'cl))
+
+(require 'eieio)
+
+(require 'jupiter)
+
+(require 'rudel-state-machine)
+
+(require 'rudel-obby-errors)
+(require 'rudel-obby-util)
+(require 'rudel-obby-state)
+
+
+;;; Class rudel-obby-server-state-new
+;;
+
+(defclass rudel-obby-server-state-new
+  (rudel-obby-server-connection-state)
+  ()
+  "State in which new connections start out.")
+
+(defmethod rudel-enter ((this rudel-obby-server-state-new))
+  "Sends welcome messages to the client and starts the session
+timeout timer."
+  ;; Send greeting sequence to the client.
+  (rudel-send this
+	      "obby_welcome"
+	      (number-to-string rudel-obby-protocol-version))
+
+  ;; Switch to encryption negotiation state.
+  'encryption-negotiate)
+
+
+;;; Class rudel-obby-server-state-encryption-negotiate
+;;
+
+(defclass rudel-obby-server-state-encryption-negotiate
+  (rudel-obby-server-connection-state)
+  ()
+  "Encryption negotiation state.")
+
+(defmethod rudel-enter ((this rudel-obby-server-state-encryption-negotiate))
+  "Send net6 'encryption' message requesting to not enable encryption."
+  (rudel-send this "net6_encryption" "0")
+  nil)
+
+(defmethod rudel-obby/net6_encryption_ok
+  ((this rudel-obby-server-state-encryption-negotiate))
+  "Handle net6 'encryption_ok' message.
+Even if the client requests an encrypted connection, we cancel
+the negotiation."
+  (rudel-send this "net6_encryption_failed")
+  'before-join)
+
+(defmethod rudel-obby/net6_encryption_failed
+  ((this rudel-obby-server-state-encryption-negotiate))
+  "Handle net6 'encryption_failed' message.
+No action has to be taken, since the client simply proceeds after
+failed encryption negotiation."
+  'before-join)
+
+
+;;; Class rudel-obby-server-state-before-join
+;;
+
+(defclass rudel-obby-server-state-before-join
+  (rudel-obby-server-connection-state)
+  ()
+  "Waiting for client request joining the session.")
+
+(defmethod rudel-obby/net6_client_login
+  ((this rudel-obby-server-state-before-join) username color
+   &optional global-password user-password)
+  "Handle net6 'client_login' message."
+  (with-parsed-arguments ((color color))
+    (with-slots (server
+		 (client-id :id)
+		 user
+		 encryption) (oref this :connection)
+      ;; Make sure USERNAME and COLOR are valid.
+      (let ((error (rudel-check-username-and-color
+		    server username color)))
+	(if error
+	    ;; If USERNAME or COLOR are invalid, send the error code
+	    ;; to the client and stay in the current state.
+	    (progn
+	      (rudel-send this
+			  "net6_login_failed"
+			  (format "%x" error))
+	      nil)
+
+	  ;; Create a user object for this client and add it to the
+	  ;; server.
+	  (setq user (rudel-make-user
+		      server
+		      username client-id color encryption))
+	  (rudel-add-user server user)
+
+	  ;; Broadcast the join event to all clients (including the
+	  ;; new one).
+	  (with-slots ((name :object-name) color (user-id :user-id)) user
+	    (rudel-broadcast this (list 'exclude (oref this :connection))
+			     "net6_client_join"
+			     (format "%x" client-id)
+			     name
+			     "0"
+			     (format "%x" user-id)
+			     (rudel-obby-format-color color)))
+
+	  ;; Get the new client up to date:
+	  ;; - transmit user list
+	  ;;   - connected users
+	  ;;   - disconnected users
+	  ;; - transmit document list
+	  (with-slots (users clients documents) server
+	    ;; Send number of synchronization items: sum of numbers of
+	    ;; offline users and documents.
+	    (let ((number-of-items (+ (length users) (length documents))))
+	      (rudel-send this
+			  "obby_sync_init"
+			  (format "%x" number-of-items)))
+
+	    ;; Transmit list of connected users.
+	    (dolist (client clients)
+	      (with-slots ((client-id :id) user) client
+		(when user
+		  (with-slots ((name    :object-name)
+			       color
+			       (user-id :user-id)) user
+		    (rudel-send this
+				"net6_client_join"
+				(format "%x" client-id)
+				name
+				"0"
+				(format "%x" user-id)
+				(rudel-obby-format-color color))))))
+
+	    ;; Transmit list of disconnected users.
+	    (let ((offline-users (remove-if #'rudel-connected users)))
+	      (dolist (user offline-users)
+		(with-slots ((name :object-name) user-id color) user
+		  (rudel-send this
+			      "obby_sync_usertable_user"
+			      (format "%x" user-id)
+			      name
+			      (rudel-obby-format-color color)))))
+
+	    ;; Transmit document list
+	    (dolist (document documents)
+	      (with-slots ((name      :object-name)
+			   (doc-id    :id)
+			   owner-id
+			   suffix
+			   subscribed) document
+		(apply #'rudel-send
+		       this
+		       "obby_sync_doclist_document"
+		       (format "%x" owner-id)
+		       (format "%x" doc-id)
+		       name
+		       (format "%x" suffix)
+		       "UTF-8"
+		       (mapcar
+			(lambda (user1) ;; TODO we could use `user' here, but there is a bug in cl
+			  (format "%x" (rudel-id user1)))
+			subscribed)))))
+
+	  (rudel-send this "obby_sync_final")
+	  'idle))))
+  )
+
+
+;;; Class rudel-obby-server-state-idle
+;;
+
+(defclass rudel-obby-server-state-idle
+  (rudel-obby-server-connection-state)
+  ()
+  "Idle state of a server connection.
+
+The connection enters this state when all setup work is finished,
+the client has joined the session and no operation is in
+progress. In this state, the connection waits for new messages
+from the client that initiate operations. Simple (which means
+stateless in this case) operations are performed without leaving
+the idle state.")
+
+(defmethod rudel-obby/obby_user_colour
+  ((this rudel-obby-server-state-idle) color-)
+  "Handle obby 'user_colour' message.
+This method is called when the connected user requests a change
+of her color to COLOR."
+  (with-parsed-arguments ((color- color))
+    (with-slots (user) (oref this :connection)
+      (with-slots (color (user-id :user-id)) user
+	;; Set color slot value.
+	(setq color color-)
+
+	;; Run change hook.
+	(object-run-hook-with-args user 'change-hook)
+
+	(rudel-broadcast this (list 'exclude (oref this :connection))
+			 "obby_user_colour"
+			 (format "%x" user-id)
+			 (rudel-obby-format-color color)))))
+  nil)
+
+(defmethod rudel-obby/obby_document_create
+  ((this rudel-obby-server-state-idle)
+   doc-id name encoding content)
+  "Handle obby 'document_create' message."
+  (with-parsed-arguments ((doc-id   number)
+			  (encoding coding-system))
+    (with-slots (user server) (oref this :connection)
+      (with-slots ((user-id :user-id)) user
+	;; Create a (hidden) buffer for the new document.
+	(let* ((buffer         (get-buffer-create
+				(generate-new-buffer-name
+				 (concat " *"  name "*"))))
+	       ;; Create the new document object
+	       (document       (rudel-obby-document
+				name
+				:buffer     buffer
+				:subscribed (list user)
+				:id         doc-id
+				:owner-id   user-id
+				:suffix     1)))
+
+	  ;; Initialize the buffer's content
+	  (with-current-buffer buffer
+	    (insert content))
+
+	  (with-slots (suffix) document
+	    ;; Determine an appropriate suffix to provide an unique
+	    ;; name for the new document.
+	    (while (rudel-find-document server
+					(if (= suffix 1)
+					    name
+					  (format "%s<%d>" name suffix))
+					#'string= #'rudel-unique-name)
+	      (incf suffix))
+
+	    ;; Add the document to the server's document list
+	    (rudel-add-document server document)
+
+	    ;; Maybe notify the creating client of the changed suffix.
+	    (unless (= suffix 1)
+	      (rudel-send this
+			  "obby_document"
+			  (format "%x %x" user-id doc-id)
+			  "rename"
+			  (format "%x" user-id)
+			  name
+			  (format "%x" suffix)))
+
+	    ;; Notify other clients of the new document
+	    (rudel-broadcast this (list 'exclude  (oref this :connection))
+			     "obby_document_create"
+			     (format "%x" user-id)
+			     (format "%x" doc-id)
+			     name
+			     (format "%x" suffix)
+			     (upcase (symbol-name encoding))))
+
+	  ;; Add a jupiter context for (THIS DOCUMENT).
+	  (rudel-add-context server (oref this :connection) document))))
+    nil)
+  )
+
+(defmethod rudel-obby/obby_document
+  ((this rudel-obby-server-state-idle) doc-id action &rest arguments)
+  "Handle obby 'document' messages."
+  (with-parsed-arguments ((doc-id document-id))
+    ;; Locate the document based on owner id and document id
+    (let ((document (with-slots (server) (oref this :connection)
+		      (rudel-find-document server doc-id
+					   #'equal #'rudel-both-ids))))
+      (rudel-obby-dispatch this action
+			   (append (list document) arguments)
+			   "rudel-obby/obby_document/")))
+  )
+
+(defmethod rudel-obby/obby_document/subscribe
+  ((this rudel-obby-server-state-idle) document user-id)
+  "Handle 'subscribe' submessage of obby 'document' message."
+  (with-parsed-arguments ((user-id number))
+    (let ((user (with-slots (server) (oref this :connection)
+		  (rudel-find-user server user-id
+				   #'= #'rudel-id))))
+      (with-slots (owner-id (doc-id :id) subscribed buffer) document
+
+	;; Track subscription, handle duplicate subscription requests.
+	(when (memq user subscribed)
+	  (error "User `%s' already subscribed to document `%s'"
+		 (object-name user) (object-name document)))
+	(rudel-add-user document user)
+
+	;; Synchronize the buffer content to the client.
+	(with-current-buffer buffer
+	  ;; Send overall buffer size
+	  (rudel-send this
+		      "obby_document"
+		      (format "%x %x" owner-id doc-id)
+		      "sync_init"
+		      (format "%x" (1- (position-bytes (point-max)))))
+
+	  ;; Send buffer chunks with author ids
+	  (dolist (chunk (rudel-chunks document))
+	    (multiple-value-bind (from to author) chunk
+	      (let ((string (buffer-substring (+ from 1) (+ to 1))))
+		(rudel-send this
+			    "obby_document"
+			    (format "%x %x" owner-id doc-id)
+			    "sync_chunk"
+			    string
+			    (format "%x"
+				    (if author
+					(oref author :user-id)
+				      0)))))))
+
+	;; Notify clients of the new subscription (including our own
+	;; client, who requested the subscription).
+	(with-slots ((user-id :user-id)) user
+	  (rudel-broadcast this nil
+			   "obby_document"
+			   (format "%x %x" owner-id doc-id)
+			   "subscribe"
+			   (format "%x" user-id)))))
+
+    ;; Add a jupiter context for (THIS document).
+    (with-slots (server) (oref this :connection)
+      (rudel-add-context server (oref this :connection) document))
+    nil)
+  )
+
+(defmethod rudel-obby/obby_document/unsubscribe
+  ((this rudel-obby-server-state-idle) document user-id)
+  "Handle 'unsubscribe' submessage of 'obby_document' message."
+  (with-parsed-arguments ((user-id number))
+    (let ((user (with-slots (server) (oref this :connection)
+		  (rudel-find-user server user-id
+				   #'= #'rudel-id))))
+      (with-slots (owner-id (doc-id :id) subscribed) document
+
+	;; Track subscription, handle invalid unsubscribe requests
+	(unless (memq user subscribed)
+	  (error "User `%s' not subscribed to document `%s'"
+		 (object-name user) (object-name document)))
+	(rudel-remove-user document user)
+
+	;; Notify clients of the canceled subscription (including our
+	;; own client, who requested being unsubscribed).
+	(with-slots ((user-id :user-id)) user
+	  (rudel-broadcast this nil
+			   "obby_document"
+			   (format "%x %x" owner-id doc-id)
+			   "unsubscribe"
+			   (format "%x" user-id))))
+
+      ;; Remove jupiter context for (THIS DOCUMENT).
+      (with-slots (server) (oref this :connection)
+	(rudel-remove-context server (oref this :connection) document)))
+    nil)
+  )
+
+(defmethod rudel-obby/obby_document/record
+  ((this rudel-obby-server-state-idle)
+   document local-revision remote-revision action &rest arguments)
+  "Handle 'record' submessages of 'obby_document' message."
+  (with-parsed-arguments ((local-revision  number)
+			  (remote-revision number))
+    ;; Dispatch to specialized operation handlers.
+    (rudel-obby-dispatch
+     this action
+     (append (list document local-revision remote-revision)
+	     arguments)
+     "rudel-obby/obby_document/record/"))
+  )
+
+(defmethod rudel-obby/obby_document/record/ins
+  ((this rudel-obby-server-state-idle)
+   document local-revision remote-revision position data)
+  "Handle 'ins' submessage of 'record' submessages of 'obby_document' message."
+  (with-parsed-arguments ((position number))
+    ;; Construct the operation object and process it.
+    (rudel-remote-operation
+     (oref this :connection) document
+     remote-revision local-revision
+     (jupiter-insert
+      (format "insert-%d-%d"
+	      remote-revision local-revision)
+      :from position
+      :data data))
+    nil)
+  )
+
+(defmethod rudel-obby/obby_document/record/del
+  ((this rudel-obby-server-state-idle)
+   document local-revision remote-revision position length)
+  "Handle 'del' submessage of 'record' submessages of 'obby_document' message."
+  (with-parsed-arguments ((position number)
+			  (length   number))
+    ;; Construct the operation object and process it.
+    (rudel-remote-operation
+     (oref this :connection) document
+     remote-revision local-revision
+     (jupiter-delete
+      (format "delete-%d-%d"
+	      remote-revision local-revision)
+      :from position
+      :to   (+ position length)))
+    nil)
+  )
+
+
+;;; Client connection states.
+;;
+
+(defvar rudel-obby-server-connection-states
+  '((new                  . rudel-obby-server-state-new)
+    (encryption-negotiate . rudel-obby-server-state-encryption-negotiate)
+    (before-join          . rudel-obby-server-state-before-join)
+    (idle                 . rudel-obby-server-state-idle))
+  "Name symbols and classes of connection states.")
+
+
+;;; Class rudel-obby-client
+;;
+
+(defclass rudel-obby-client (rudel-obby-socket-owner
+			     rudel-state-machine)
+  ((server     :initarg  :server
+	       :type     rudel-obby-server
+	       :documentation
+	       "")
+   (id         :initarg  :id
+	       :type     integer
+	       :accessor rudel-id
+	       :documentation
+	       "")
+   (user       :initarg  :user
+	       :type     (or rudel-obby-user null)
+	       :initform nil
+	       :documentation
+	       "")
+   (encryption :initarg  :encryption
+	       :type     boolean
+	       :documentation
+	       ""))
+  "Each object of this class represents one client, that is
+connected to the server. This object handles all direct
+communication with the client, while broadcast messages are
+handled by the server.")
+
+(defmethod initialize-instance ((this rudel-obby-client) &rest slots)
+  "Initialize slots of THIS and register state machine states."
+  ;; Initialize slots of THIS
+  (when (next-method-p)
+    (call-next-method))
+
+  ;; Register states.
+  (rudel-register-states this rudel-obby-server-connection-states)
+  )
+
+(defmethod rudel-register-state ((this rudel-obby-client) symbol state)
+  "Register SYMBOL and STATE and set connection slot of STATE."
+  ;; Associate THIS connection to STATE.
+  (oset state :connection this)
+
+  ;; Register STATE.
+  (call-next-method))
+
+(defmethod rudel-end ((this rudel-obby-client))
+  ""
+  (rudel-disconnect this))
+
+(defmethod rudel-close ((this rudel-obby-client))
+  ""
+  (with-slots (server) this
+    (rudel-remove-client server this)))
+
+(defmethod rudel-message ((this rudel-obby-client) message)
+  "Dispatch MESSAGE to the active state of THIS state machine."
+  ;; Dispatch message to state
+  (rudel-accept this message))
+
+(defmethod rudel-broadcast ((this rudel-obby-client)
+			    receivers name &rest arguments)
+  "Broadcast message NAME with arguments ARGUMENTS to RECEIVERS."
+  (with-slots (server) this
+    (apply #'rudel-broadcast server receivers name arguments)))
+
+(defmethod rudel-remote-operation ((this rudel-obby-client)
+				   document
+				   local-revision remote-revision
+				   operation)
+  "Execute and relay OPERATION on DOCUMENT."
+  (with-slots (server user) this
+    ;; Transform OPERATION and find clients that need to receive
+    ;; notifications.
+    (let* ((context     (rudel-find-context server this document))
+	   (transformed (jupiter-remote-operation
+			 context
+			 local-revision remote-revision
+			 operation))
+	   (receivers   (rudel-subscribed-clients-not-self
+			 this document)))
+
+      ;; Relay change notification to other clients. We use
+      ;; TRANSFORMED before the byte -> char conversion which is what
+      ;; the receivers expect.
+      (with-slots (user-id) user
+	(with-slots (owner-id (doc-id :id)) document
+	  ;; Construct and send messages to all receivers individually
+	  ;; since the contents of the messages depends on the state
+	  ;; of the jupiter context associated the respective
+	  ;; receiver.
+	  (dolist (receiver receivers)
+
+	    ;; Find the jupiter context for RECEIVER and use its
+	    ;; revision information.
+	    (let ((context (rudel-find-context server receiver document)))
+	      ;; Construct and send one message.
+	      (with-slots (local-revision remote-revision) context
+		(apply #'rudel-send
+		       receiver
+		       "obby_document"
+		       (format "%x %x" owner-id doc-id)
+		       "record"
+		       (format "%x" user-id)
+		       (format "%x" local-revision)
+		       (format "%x" remote-revision)
+		       (rudel-operation->message transformed)))
+
+	      ;; Submit the operation to the jupiter context.
+	      (jupiter-local-operation context transformed)))))
+
+      ;; Incorporate change into DOCUMENT (the server-side
+      ;; document). We have to convert bytes -> chars before we can do
+      ;; this.
+      (with-slots (buffer) document
+	(rudel-obby-byte->char transformed buffer))
+
+      (rudel-remote-operation document user transformed)))
+  )
+
+(defmethod rudel-subscribed-clients-not-self ((this rudel-obby-client)
+					      document)
+  "Return a list of clients subscribed to DOCUMENT excluding THIS."
+  (with-slots (clients) (oref this :server)
+    (with-slots (subscribed) document
+      (remove-if
+       (lambda (client)
+	 (with-slots (user) client
+	   (or (eq client this)
+	       (not (memq user subscribed)))))
+       clients)))
+  )
+
+
+;;; Class rudel-obby-server
+;;
+
+(defclass rudel-obby-server (rudel-server-session
+			     rudel-socket-owner)
+  ((clients        :initarg  :clients
+		   :type     list
+		   :initform nil
+		   :documentation
+		   "")
+   (next-client-id :initarg  :next-client-id
+		   :type     integer
+		   :initform 1
+		   :documentation
+		   "")
+   (next-user-id   :initarg  :next-user-id
+		   :type     integer
+		   :initform 1
+		   :documentation
+		   "")
+   (contexts       :initarg  :contexts
+		   :type     hash-table
+		   :documentation
+		   ""))
+  "Class rudel-obby-server ")
+
+(defmethod initialize-instance ((this rudel-obby-server) &rest slots)
+  ""
+  (when (next-method-p)
+    (call-next-method))
+
+  (with-slots (contexts) this
+    (setq contexts (make-hash-table :test 'equal))))
+
+(defmethod rudel-end ((this rudel-obby-server))
+  ""
+  (rudel-disconnect this))
+
+(defmethod rudel-broadcast ((this rudel-obby-server)
+			    receivers name &rest arguments)
+  "Send a message of type NAME with arguments ARGUMENTS to RECEIVERS.
+
+RECEIVERS can be a object derived from rudel-obby-client, a list
+of such objects or a list with car 'exclude and cdr a list of
+such objects derived from rudel-obby-client."
+  ;; Construct list of receivers.
+  (let ((receiver-list
+	 (cond
+	  ;; If RECEIVERS is nil, the message should be broadcast to
+	  ;; all clients.
+	  ((null receivers) (oref this :clients))
+	  ;; If RECEIVERS is a (non-empty) list of rudel-obby-client
+	  ;; (or derived) objects, treat it as a list of receivers.
+	  ((and (listp receivers)
+		(rudel-obby-client-child-p (car receivers)))
+	   receivers)
+	  ;; If RECEIVERS is a (non-empty) list with cdr equal to
+	  ;; 'exclude treat it as a list of receivers to exclude.
+	  ((and (listp receivers)
+		(eq (car receivers) 'exclude))
+	   (with-slots (clients) this
+	     (set-difference clients (cdr receivers)
+			     :key #'rudel-id)))
+	  ;; If RECEIVERS is a single rudel-obby-client (or derived)
+	  ;; object, send the message to that client.
+	  ((rudel-obby-client-child-p receivers)
+	   (list receivers))
+	  ;;
+	  (t (signal 'wrong-type-argument (type-of receivers))))))
+
+    ;; Send message to receivers.
+    (dolist (receiver receiver-list)
+      (apply #'rudel-send receiver name arguments)))
+  )
+
+(defmethod rudel-make-user ((this rudel-obby-server)
+			    name client-id color encryption)
+  ""
+  (with-slots (next-user-id) this
+    (let ((user (rudel-obby-user name
+                 :color      color
+		 :client-id  client-id
+		 :user-id    next-user-id
+		 :connected  t
+		 :encryption encryption)))
+      (incf next-user-id)
+      user))
+  )
+
+(defmethod rudel-check-username-and-color ((this rudel-obby-server)
+					   username color)
+  "Check whether USERNAME and COLOR are valid.
+USERNAME must not be empty and must not be used by another
+user. COLOR has to be sufficiently different from used colors."
+  (cond
+   ;; The empty user name is not allowed
+   ((string= username "")
+    rudel-obby-error-username-invalid)
+
+   ;; Make sure the user name is not already in use.
+   ((rudel-find-user this username
+		     #'string= #'object-name-string)
+    rudel-obby-error-username-in-use)
+
+   ;; Make sure the color is sufficiently dissimilar to all used
+   ;; colors.
+   ((rudel-find-user this color
+		     (lambda (left right)
+		       (< (color-distance left right) 20000)) ;; TODO constant
+		     #'rudel-color)
+    rudel-obby-error-color-in-use))
+  )
+
+(defmethod rudel-add-client ((this rudel-obby-server)
+			     client-socket)
+  ""
+  (with-slots (next-client-id clients) this
+    (let ((client (rudel-obby-client (process-name client-socket)
+		   :server     this
+		   :socket     client-socket
+		   :id         next-client-id
+		   :encryption nil)))
+      (push client clients))
+    (incf next-client-id))
+  )
+
+(defmethod rudel-remove-client ((this rudel-obby-server)
+				client)
+  ""
+  (with-slots ((client-id :id) user) client
+    ;; Broadcast the part event to all remaining clients.
+    (rudel-broadcast this (list 'exclude client)
+		     "net6_client_part"
+		     (format "%x" client-id))
+
+    ;; If the client has an associated user object, set the status of
+    ;; the user object to offline.
+    (when user
+      ;; Set slot value.
+      (with-slots (connected) user
+	(setq connected nil))
+
+      ;; Run change hook.
+      (object-run-hook-with-args user 'change-hook)))
+
+  (object-remove-from-list this :clients client)
+  )
+
+(defmethod rudel-find-context ((this rudel-obby-server) client document)
+  "Return the jupiter context associated to (CLIENT DOCUMENT) in THIS."
+  (with-slots (contexts) this
+    (gethash (rudel-obby-context-key client document) contexts)))
+
+(defmethod rudel-add-context ((this rudel-obby-server) client document)
+  "Add a jupiter context for (CLIENT DOCUMENT) to THIS."
+  (with-slots (contexts) this
+    (with-slots ((client-id :id)) client
+      (with-slots ((doc-name :object-name)) document
+	(puthash
+	 (rudel-obby-context-key client document)
+	 (jupiter-context (format "%d-%s" client-id doc-name))
+	 contexts))))
+  )
+
+(defmethod rudel-remove-context ((this rudel-obby-server) client document)
+  "Remove the jupiter context associated to (CLIENT DOCUMENT) from THIS."
+  (with-slots (contexts) this
+    (remhash
+     (rudel-obby-context-key client document)
+     contexts)))
+
+(defun rudel-obby-context-key (client document)
+  "Generate hash key based on CLIENT and DOCUMENT."
+  (with-slots ((client-id :id)) client
+    (with-slots ((doc-id :id)) document
+      (list client-id doc-id))))
+
+(defmethod object-print ((this rudel-obby-server) &rest strings)
+  "Print THIS with number of clients."
+  (with-slots (clients) this
+    (apply #'call-next-method
+	   this
+	   (format " clients: %d"
+		   (length clients))
+	   strings))
+  )
+
+(provide 'rudel-obby-server)
+;;; rudel-obby-server.el ends here
diff --git a/emacs.d/lisp/rudel/obby/rudel-obby-state.el b/emacs.d/lisp/rudel/obby/rudel-obby-state.el
new file mode 100644
index 0000000..a190967
--- /dev/null
+++ b/emacs.d/lisp/rudel/obby/rudel-obby-state.el
@@ -0,0 +1,169 @@
+;;; rudel-obby-state.el --- Base class for states used in the obby backend
+;;
+;; Copyright (C) 2009 Jan Moringen
+;;
+;; Author: Jan Moringen <scymtym@users.sourceforge.net>
+;; Keywords: Rudel, obby, state machine
+;; X-RCS: $Id:$
+;;
+;; This file is part of Rudel.
+;;
+;; Rudel is free software: you can redistribute it and/or modify it
+;; under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+;;
+;; Rudel is distributed in the hope that it will be useful, but
+;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+;; General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with Rudel. If not, see <http://www.gnu.org/licenses>.
+
+
+;;; Commentary:
+;;
+;; This file contains a base class for finite state machine states
+;; used in the obby backend.
+
+
+;;; History:
+;;
+;; 0.1 - Initial revision
+
+
+;;; Code:
+;;
+
+(require 'eieio)
+
+(require 'rudel-util)
+(require 'rudel-state-machine)
+
+(require 'rudel-obby-util)
+
+
+;;; Class rudel-obby-state
+;;
+
+(defclass rudel-obby-state (rudel-state)
+  ((connection :initarg :connection
+	       :type    rudel-obby-socket-owner
+	       :documentation
+	       "Connection object that uses the state."))
+  "Base class for state classes used in the obby backend."
+  :abstract t)
+
+(defmethod rudel-enter ((this rudel-obby-state))
+  "Default behavior is doing nothing when entering a state."
+  nil)
+
+(defmethod rudel-leave ((this rudel-obby-state))
+  "Default behavior is doing nothing when leaving a state.")
+
+(defmethod rudel-accept ((this rudel-obby-state) message)
+  "Dispatch to appropriate handler based on MESSAGE.
+Display a warning if no such handler is found."
+  ;; Try to dispatch to the correct message handler. If there is none,
+  ;; warn.
+  (let ((name      (car message))
+	(arguments (cdr message)))
+    (condition-case error
+	;; Try to dispatch
+	(rudel-dispatch this "rudel-obby/" name arguments)
+      ;; Warn if we failed to locate or execute the method. Return nil
+      ;; in this case, so we remain in the current state.
+      (rudel-dispatch-error
+       (progn
+	 (display-warning
+	  '(rudel obby)
+	  (format "%s: no method (%s: %s): `%s/%s'; arguments: %s"
+		  (object-print this) (car error) (cdr error)
+		  "rudel-obby" name arguments)
+	  :debug)
+	 nil))))
+  )
+
+(defmethod rudel-send ((this rudel-obby-state) &rest args)
+  "Send ARGS through the connection associated with THIS."
+  (with-slots (connection) this
+    (apply #'rudel-send connection args)))
+
+
+;;; Class rudel-obby-client-connection-state
+;;
+
+(defclass rudel-obby-client-connection-state (rudel-obby-state)
+  ()
+  "Base class for state classes used by obby client connections."
+  :abstract t)
+
+(defmethod rudel-obby/net6_ping ((this rudel-obby-client-connection-state))
+  "Handle net6 'ping' message."
+  (rudel-send this "net6_pong")
+  nil)
+
+
+;;; Class rudel-obby-server-connection-state
+;;
+
+(defclass rudel-obby-server-connection-state (rudel-obby-state)
+  ()
+  "Base class for server connection states."
+  :abstract t)
+
+(defmethod rudel-broadcast ((this rudel-obby-server-connection-state)
+			    receivers name &rest arguments)
+  "Broadcast message NAME with arguments ARGUMENTS to RECEIVERS."
+  (with-slots (connection) this
+    (apply #'rudel-broadcast connection receivers name arguments)))
+
+
+;;; Class rudel-obby-document-handler
+;;
+
+(defclass rudel-obby-document-handler ()
+  ()
+  "Mixin class that provides ability to process submessages of
+  obby 'document' messages.")
+
+(defmethod rudel-obby/obby_document
+  ((this rudel-obby-document-handler) doc-id action &rest arguments)
+  "Handle obby 'document' message family."
+  ;; Try to dispatch to the correct message handler. If there is none,
+  ;; warn.
+  (with-parsed-arguments ((doc-id document-id))
+    ;; Locate the document based on owner id and document id.
+    (let ((document (with-slots (connection) this
+		      (with-slots (session) connection
+			(rudel-find-document session doc-id
+					     #'equal #'rudel-both-ids)))))
+      (if document
+	  (condition-case error
+	      ;; Try to dispatch
+	      (rudel-dispatch this "rudel-obby/obby_document/" action
+			      (cons document arguments))
+	    ;; Warn if we failed to locate or execute the
+	    ;; method. Return nil in this case, so we remain in the
+	    ;; current state.
+	    (rudel-dispatch-error
+	     (progn
+	       (display-warning
+		'(rudel obby)
+		(format "%s: no method (%s: %s): `%s:%s'; arguments: %s"
+			(object-print this) (car error) (cdr error)
+			"rudel-obby/obby_document/" action arguments)
+		:debug)
+	       nil)))
+	;; If we did not find the document, warn.
+	(progn
+	  (display-warning
+	   '(rudel obby)
+	   (format "Document not found: %s" doc-id)
+	   :debug)
+	  nil))))
+  )
+
+(provide 'rudel-obby-state)
+;;; rudel-obby-state.el ends here
diff --git a/emacs.d/lisp/rudel/obby/rudel-obby-util.el b/emacs.d/lisp/rudel/obby/rudel-obby-util.el
new file mode 100644
index 0000000..faefe70
--- /dev/null
+++ b/emacs.d/lisp/rudel/obby/rudel-obby-util.el
@@ -0,0 +1,314 @@
+;;; rudel-obby-util.el --- Miscellaneous functions for the Rudel obby backend
+;;
+;; Copyright (C) 2008, 2009 Jan Moringen
+;;
+;; Author: Jan Moringen <scymtym@users.sourceforge.net>
+;; Keywords: Rudel, obby, backend, miscellaneous
+;; X-RCS: $Id:$
+;;
+;; This file is part of Rudel.
+;;
+;; Rudel is free software: you can redistribute it and/or modify it
+;; under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+;;
+;; Rudel is distributed in the hope that it will be useful, but
+;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+;; General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with Rudel. If not, see <http://www.gnu.org/licenses>.
+
+
+;;; Commentary:
+;;
+;;
+
+
+;;; History:
+;;
+;; 0.1 - Initial revision.
+
+
+;;; Code:
+;;
+
+(eval-when-compile
+  (require 'cl))
+
+(require 'eieio)
+
+(require 'rudel)
+(require 'rudel-util)
+
+(require 'jupiter)
+
+
+;;; Class rudel-obby-socket-owner
+;;
+
+(defclass rudel-obby-socket-owner (rudel-socket-owner)
+  ((buffer :initarg  :buffer
+	   :type     (or null string)
+	   :initform nil
+	   :documentation
+	   "Stores message fragments until complete messages can
+be assembled."))
+  "This class adds functions for sending and receiving obby
+messages to the base class rudel-socket-owner.")
+
+(defmethod rudel-send ((this rudel-obby-socket-owner)
+		       name &rest arguments)
+  "Send obby message NAME with arguments ARGUMENTS through the socket associated to THIS."
+  (with-slots (socket) this
+    (rudel-obby-send socket name arguments)))
+
+(defmethod rudel-receive ((this rudel-obby-socket-owner) data)
+  "Reassemble lines in DATA received on the socket associated with THIS and call message handler."
+  ;; Assemble fragmented lines.
+  (with-slots (buffer) this
+    (rudel-assemble-line-fragments data buffer))
+
+  ;; Process all available lines.
+  (rudel-loop-lines data line
+    ;; `rudel-message' has to dispatch message to an appropriate
+    ;; handler.
+    (let ((message (rudel-obby-parse-message line)))
+      (rudel-message this message)))
+  )
+
+(defgeneric rudel-message ((this rudel-obby-socket-owner) message)
+  "Called when a message arrives.
+Should be implemented in derived classes.")
+
+
+;;; Message serialization
+;;
+
+(defgeneric rudel-operation->message ((this jupiter-operation))
+  "Generate a list obby message components from THIS operation.")
+
+(defmethod rudel-operation->message ((this jupiter-insert))
+  "Serialize THIS insert operation."
+  (with-slots (from data) this
+    (list "ins" (format "%x" from) data)))
+
+(defmethod rudel-operation->message ((this jupiter-delete))
+  "Serialize THIS delete operation."
+  (with-slots (from length) this
+    (list "del" (format "%x" from) (format "%x" length))))
+
+(defmethod rudel-operation->message ((this jupiter-compound))
+  "Serialize THIS compound operation."
+  (with-slots (children) this
+    (apply #'append
+	   (list "split" )
+	   (mapcar #'rudel-operation->message children))))
+
+(defmethod rudel-operation->message ((this jupiter-nop))
+  "Serialize THIS nop operation."
+  (list "nop"))
+
+(defun rudel-message->operation (message local-revision remote-revision)
+  "Construct an operation object from MESSAGE and LOCAL-REVISION and REMOTE-REVISION.
+LOCAL-REVISION and REMOTE-REVISION are only used in the
+construction of the name of the new operation. "
+  (let ((type (car message)))
+    (cond
+
+     ;; Insert operation
+     ((string= type "ins")
+      (let ((position-numeric (string-to-number (nth 1 message) 16))
+	    (data             (nth 2 message)))
+	(jupiter-insert
+	 (format "insert-%d-%d"
+		 remote-revision local-revision)
+	 :from position-numeric
+	 :data data)))
+
+     ;; Delete operation
+     ((string= type "del")
+      (let ((position-numeric (string-to-number (nth 1 message) 16))
+	    (length-numeric   (string-to-number (nth 2 message) 16)))
+	(jupiter-delete
+	 (format "delete-%d-%d"
+		 remote-revision local-revision)
+	 :from position-numeric
+	 :to   (+ position-numeric length-numeric))))
+
+     ;; Compound operation
+     ((string= type "split")
+      (let* ((rest   (cdr message))
+	     (offset (position-if
+		       (lambda (item)
+			 (member* item '("ins" "del" "nop")
+				  :test #'string=))
+		       rest
+		       :start 1))
+	     (first  (subseq rest 0 offset))
+	     (second (subseq rest offset)))
+	(jupiter-compound
+	 (format "compound-%d-%d"
+		 remote-revision local-revision)
+	 :children
+	 (list (rudel-message->operation
+		first local-revision remote-revision)
+	       (rudel-message->operation
+		second local-revision remote-revision)))))
+
+     ;; No operation
+     ((string= type "nop")
+      (jupiter-nop
+       (format "nop-%d-%d"
+	       remote-revision local-revision)))
+
+     ;; Unknown operation type
+     (t (error "Unknown document record type: `%s'" type))))
+  )
+
+
+;;; Character <-> byte position conversion
+;;
+
+(defgeneric rudel-obby-char->byte ((this jupiter-operation) buffer)
+  "Convert character positions and lengths in THIS to bytes.")
+
+(defmethod rudel-obby-char->byte ((this jupiter-insert) buffer)
+  "Convert character positions and lengths in THIS insert to bytes."
+  (with-slots (from) this
+    (with-current-buffer buffer
+      (setq from (- (position-bytes (+ from 1)) 1)))))
+
+(defmethod rudel-obby-char->byte ((this jupiter-delete) buffer)
+ "Convert character positions and lengths in THIS delete to bytes."
+  (with-slots (from to length) this
+    (let ((old-from (+ from 1))
+	  (old-to   (+ to   1)))
+      (with-current-buffer buffer
+	(destructuring-bind (change-from change-to string)
+	    rudel-buffer-change-workaround-data
+	  (setq from   (- (position-bytes old-from) 1)
+		length (string-bytes
+			(substring string
+				   (- old-from change-from)
+				   (- old-to   change-from))))))))
+  )
+
+(defmethod rudel-obby-char->byte ((this jupiter-compound) buffer)
+  "Convert character positions and lengths in THIS compound to bytes.."
+  (with-slots (children) this
+    (mapc
+     (lambda (child)
+       (rudel-obby-char->byte child buffer))
+     children))
+  )
+
+(defmethod rudel-obby-char->byte ((this jupiter-nop) buffer)
+  "Nothing to convert if THIS is a nop.")
+
+(defgeneric rudel-obby-byte->char ((this jupiter-operation) buffer)
+  "Convert byte positions and lengths in THIS to character positions.")
+
+(defmethod rudel-obby-byte->char ((this jupiter-insert) buffer)
+  "Convert byte positions and lengths in THIS insert to character positions."
+  (with-slots (from) this
+    (with-current-buffer buffer
+      (setq from (- (byte-to-position (+ from 1)) 1)))))
+
+(defmethod rudel-obby-byte->char ((this jupiter-delete) buffer)
+  "Convert byte positions and lengths in THIS delete to character positions."
+  (with-slots (from to length) this
+    (let ((old-from   from)
+	  (old-length length))
+      (with-current-buffer buffer
+	(setq from (- (byte-to-position (+ old-from 1)) 1)
+	      to   (- (byte-to-position (+ old-from old-length 1)) 1)))))
+  )
+
+(defmethod rudel-obby-byte->char ((this jupiter-compound) buffer)
+  "Convert byte positions and lengths in THIS compound to character positions."
+  (with-slots (children) this
+    (mapc
+     (lambda (child)
+       (rudel-obby-byte->char child buffer))
+     children))
+  )
+
+(defmethod rudel-obby-byte->char ((this jupiter-nop) buffer)
+  "Nothing to convert if THIS is a nop.")
+
+
+;;; Miscellaneous functions
+;;
+
+(defun rudel-obby-dispatch (object name arguments &optional prefix)
+  "Call method starting with PREFIX and ending in NAME of OBJECT with ARGUMENTS.
+When PREFIX is not specified, \"rudel-obby/\" is used."
+  ;; Default prefix.
+  (unless prefix
+    (setq prefix "rudel-obby/"))
+
+  ;; Construct a matching symbol.
+  (let ((method (intern-soft (concat prefix name))))
+    ;; If we found a suitable method, run it; Otherwise warn and do
+    ;; nothing.
+    (unless (and method
+		 (condition-case error
+		     ;; Try to call METHOD. If successful, always
+		     ;; return t.
+		     (progn
+		       (apply method object arguments)
+		       t)
+		   ;; Warn only when the condition is
+		   ;; 'no-method-definition' and refers to METHOD,
+		   ;; otherwise continue unwinding.
+		   (no-method-definition
+		    (if (eq method (cadr error))
+			nil
+		      (signal (car error) (cdr error))))))
+      (display-warning
+       '(rudel obby)
+       (format "%s: in context `%s': no method: `%s'; arguments: %s"
+	       (object-name-string object) prefix name arguments)
+       :debug)))
+  )
+
+(defmacro with-parsed-arguments (specs &rest forms)
+  "Execute FORMS with variable bindings according to SPECS.
+SPECS is structured as follows:
+SPECS   ::= (BINDING*)
+BINDING ::= (VAR TYPE)
+VAR is a symbol and TYPE is one of number, color, document-id and
+coding-system."
+  (declare (indent 1)
+	   (debug (listp &rest form)))
+  (let ((bindings
+	 (mapcar
+	  (lambda (spec)
+	    (destructuring-bind (var type) spec
+	      (list var
+		    (case type
+		      ;; Number
+		      (number
+		       `(string-to-number ,var 16))
+		      ;; Color
+		      (color
+		       `(rudel-obby-parse-color ,var))
+		      ;; Document Id
+		      (document-id
+		       `(mapcar
+			 (lambda (string)
+			   (string-to-number string 16))
+			 (split-string ,var " " t)))
+		      ;; Coding System
+		      (coding-system
+		       `(rudel-get-coding-system (downcase ,var)))))))
+	  specs)))
+    `(let (,@bindings)
+       ,@forms))
+  )
+
+(provide 'rudel-obby-util)
+;;; rudel-obby-util.el ends here
diff --git a/emacs.d/lisp/rudel/obby/rudel-obby.el b/emacs.d/lisp/rudel/obby/rudel-obby.el
new file mode 100644
index 0000000..a09c0d3
--- /dev/null
+++ b/emacs.d/lisp/rudel/obby/rudel-obby.el
@@ -0,0 +1,488 @@
+;;; rudel-obby.el --- An obby backend for Rudel
+;;
+;; Copyright (C) 2008, 2009 Jan Moringen
+;;
+;; Author: Jan Moringen <scymtym@users.sourceforge.net>
+;; Keywords: Rudel, obby, backend, implementation
+;; X-RCS: $Id:$
+;;
+;; This file is part of Rudel.
+;;
+;; Rudel is free software: you can redistribute it and/or modify it
+;; under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+;;
+;; Rudel is distributed in the hope that it will be useful, but
+;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+;; General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with Rudel. If not, see <http://www.gnu.org/licenses>.
+
+
+;;; Commentary:
+;;
+;; This file contains a Rudel protocol backend, which implements the
+;; obby protocol (used by the Gobby collaborative editor until version
+;; 0.5).
+
+
+;;; History:
+;;
+;; 0.2 - Refactored client and server to employ state machine.
+;;
+;; 0.1 - Initial revision.
+
+
+;;; Code:
+;;
+
+(eval-when-compile
+  (require 'cl))
+
+(require 'eieio)
+
+(require 'rudel)
+(require 'rudel-backend)
+(require 'rudel-protocol)
+(require 'rudel-util)
+(require 'rudel-icons)
+(require 'rudel-compat) ;; for `read-color' replacement
+
+
+;;; Constants
+;;
+
+(defconst rudel-obby-version '(0 2)
+  "Version of the obby backend for Rudel.")
+
+(defconst rudel-obby-protocol-version 8
+  "Version of the obby protocol this library understands.")
+
+(defvar rudel-obby-long-message-threshold 32768
+  "Threshold for message size, above which messages are sent in
+multiple chunks.")
+
+(defvar rudel-obby-long-message-chunk-size 16384
+  "Chunk size used, when chunking long messages.")
+
+
+;;; Class rudel-obby-backend
+;;
+
+;;;###autoload
+(defclass rudel-obby-backend (rudel-protocol-backend)
+  ((capabilities :initform '(join host
+			     change-color
+			     track-subscriptions)))
+  "Main class of the Rudel obby backend. Creates obby client
+connections and creates obby servers.")
+
+(defmethod initialize-instance ((this rudel-obby-backend) &rest slots)
+  "Initialize slots of THIS with SLOTS."
+  (when (next-method-p)
+    (call-next-method))
+
+  (oset this :version rudel-obby-version))
+
+(defmethod rudel-ask-connect-info ((this rudel-obby-backend) &optional info)
+  "Ask user for the information required to connect to an obby server."
+  ;; Read server host and port.
+  (let ((host            (or (and info (plist-get info :host))
+			     (read-string "Server: ")))
+	(port            (or (and info (plist-get info :port))
+			     (read-number "Port: " 6522)))
+	;; Read desired username and color
+	(username        (or (and info (plist-get info :username))
+			     (read-string "Username: " user-login-name)))
+	(color           (or (and info (plist-get info :color))
+			     (read-color  "Color: " t)))
+	(encryption      (if (and info (member :encryption info))
+			     (plist-get info :encryption)
+			   (y-or-n-p "Use encryption? ")))
+	(global-password (if (and info (member :global-password info))
+			     (plist-get info :global-password)
+			   (read-string "Global password: " "")))
+	(user-password   (if (and info (member :user-password info))
+			     (plist-get info :user-password)
+			   (read-string "User password: " ""))))
+    (append (list :host            host
+		  :port            port
+		  :username        username
+		  :color           color
+		  :encryption      encryption
+		  :global-password (unless (string= global-password "")
+				     global-password)
+		  :user-password   (unless (string= user-password "")
+				     user-password))
+	    info))
+  )
+
+(defmethod rudel-connect ((this rudel-obby-backend) info)
+  "Connect to an obby server using the information INFO.
+Return the connection object."
+  ;; Before we start, load the client functionality.
+  (require 'rudel-obby-client)
+
+  ;; Create the network process
+  (let* ((session    (plist-get info :session))
+	 (host       (plist-get info :host))
+	 (port       (plist-get info :port))
+	 (encryption (plist-get info :encryption))
+	 ;; Create the network process
+	 (socket     (funcall
+		      (if encryption
+			  (progn
+			    (require 'rudel-tls)
+			    #'rudel-tls-make-process)
+			#'make-network-process)
+		      :name     host
+		      :host     host
+		      :service  port
+		      ;; Install connection filter to redirect data to
+		      ;; the connection object
+		      :filter   #'rudel-filter-dispatch
+		      ;; Install connection sentinel to redirect state
+		      ;; changes to the connection object
+		      :sentinel #'rudel-sentinel-dispatch
+		      ;; Do not start receiving immediately since the
+		      ;; filter function is not yet setup properly.
+		      :stop     t))
+	 (connection (rudel-obby-connection
+		      host
+		      :session session
+		      :socket  socket
+		      :info    info)))
+
+    ;; Now start receiving and wait until the basic session setup is
+    ;; complete.
+    (continue-process socket)
+
+    ;; Wait for the connection to reach one of the states idle,
+    ;; join-failed and they-finalized.
+    (condition-case error
+	(lexical-let ((reporter (make-progress-reporter "Joining ")))
+	  (flet ((display-progress (state)
+	           (cond
+		    ;; For all states, just spin.
+		    ((consp state)
+		     (progress-reporter-force-update
+                      reporter nil (format "Joining (%s)" (car state))))
+
+		    ;; Done
+		    (t
+		     (progress-reporter-force-update reporter nil "Joining ")
+		     (progress-reporter-done reporter)))))
+
+	    (rudel-state-wait connection
+			      '(idle) '(join-failed they-finalized)
+			      #'display-progress)))
+
+      (rudel-entered-error-state
+       (destructuring-bind (symbol . state) (cdr error)
+	 (if (eq (rudel-find-state connection 'join-failed) state)
+	     (with-slots (error-symbol error-data) state
+	       (signal 'rudel-join-error
+		       (append (list error-symbol) error-data)))
+	   (signal 'rudel-join-error nil)))))
+
+    ;; The connection is now usable; return it.
+    connection)
+  )
+
+(defmethod rudel-ask-host-info ((this rudel-obby-backend))
+  "Ask user for information required to host an obby session."
+  (let ((port (read-number "Port: " 6522)))
+    (list :port port)))
+
+(defmethod rudel-host ((this rudel-obby-backend) info)
+  "Host an obby session using the information INFO.
+Return the created server."
+  ;; Before we start, we load the server functionality.
+  (require 'rudel-obby-server)
+
+  ;; Create the network process.
+  (let* ((port   (plist-get info :port))
+	 ;; Make a server socket
+	 (socket (make-network-process
+		  :name     "obby-server"
+		  :host     "0.0.0.0"
+		  :service  port
+		  :server   t
+		  :filter   #'rudel-filter-dispatch
+		  :sentinel #'rudel-sentinel-dispatch
+		  ;;
+		  :log
+		  (lambda (server-process client-process message)
+		    (let ((server (rudel-process-object server-process)))
+		      (rudel-add-client server client-process)))))
+	 ;; Construct server object.
+	 (server (rudel-obby-server "obby-server"
+				    :backend this
+				    :socket  socket)))
+
+    ;; Return the constructed server.
+    server)
+  )
+
+(defmethod rudel-make-document ((this rudel-obby-backend)
+				name session)
+  "Make a new document in SESSION named NAME.
+Return the new document."
+  ;; Find an unused document id and create a document with that id.
+  (let ((id (rudel-available-document-id this session)))
+    (with-slots (user-id) (oref session :self)
+      (rudel-obby-document name
+			   :session  session
+			   :id       id
+			   :owner-id user-id
+			   :suffix   1)))
+  )
+
+(defmethod rudel-available-document-id ((this rudel-obby-backend)
+					session)
+  "Return a document id, which is not in use in SESSION."
+  ;; Look through some candidates until an unused id is hit.
+  (let* ((used-ids (with-slots (documents) session
+		     (mapcar 'rudel-id documents)))
+	 (test-ids (number-sequence 0 (length used-ids))))
+    (car (sort (set-difference test-ids used-ids) '<)))
+  )
+
+
+;;; Class rudel-obby-user
+;;
+
+(defclass rudel-obby-user (rudel-user)
+  ((client-id  :initarg  :client-id
+	       :type     (or null integer) ;; We allow nil instead of making
+	       :accessor rudel-client-id   ;; the slot unbound, to be able to
+	       :initform nil               ;; search with test `rudel-client-id
+	       :documentation              ;; without headaches
+	       "Id of the client connection, which the user used to log in.
+The value is an integer, if the user is connected, and nil
+otherwise.")
+   (user-id    :initarg  :user-id
+	       :type     integer
+	       :accessor rudel-id
+	       :documentation
+	       "")
+   (connected  :initarg  :connected
+	       :type     boolean
+	       :accessor rudel-connected
+	       :documentation
+	       "")
+   (encryption :initarg  :encryption ;; TODO maybe we should use unbound when the user is not connected
+	       :type     boolean
+	       :documentation
+	       ""))
+  "Class rudel-obby-user ")
+
+(defmethod eieio-speedbar-description ((this rudel-obby-user))
+  "Provide a speedbar description for THIS."
+  (let ((connected  (oref this :connected))
+	(encryption (if (slot-boundp this :encryption)
+			(oref this :encryption)
+		      nil)))
+    (format "User %s (%s, %s)" (object-name-string this)
+	    (if connected  "Online" "Offline")
+	    (if encryption "Encryption" "Plain")))
+  )
+
+(defmethod eieio-speedbar-object-buttonname ((this rudel-obby-user))
+  "Return a string to use as a speedbar button for THIS."
+  (rudel-display-string this))
+
+(defmethod rudel-display-string ((this rudel-obby-user)
+				 &optional use-images align)
+  "Return a textual representation of THIS for user interface stuff."
+  (with-slots (connected color) this
+    (let ((encryption  (and (slot-boundp this :encryption)
+			    (oref this :encryption)))
+	  (name-string (call-next-method)))
+      (concat
+       ;; Name bit
+       (cond
+	((numberp align) (format (format "%-%ds" align) name-string))
+	((eq align t)    (format "%-12s" name-string))
+	(t		name-string))
+
+       ;; Connection status bit
+       (apply
+	#'propertize
+	(if connected "c" "-")
+	'help-echo (format (if connected
+			       "%s is connected"
+			     "%s is not connected")
+			   name-string)
+	'face      (list :background color)
+	(when use-images
+	  (list 'display (if connected
+			     rudel-icon-connected
+			   rudel-icon-disconnected))))
+
+       ;; Encryption bit
+       (apply
+	#'propertize
+	(if encryption "e" "-")
+	'help-echo (format (if encryption
+			       "%s's connection is encrypted"
+			     "%s's connection is not encrypted")
+			   name-string)
+	'face      (list :background color)
+	(when use-images
+	  (list 'display (if encryption
+			     rudel-icon-encrypted
+			   rudel-icon-plaintext)))))))
+  )
+
+
+;;; Class rudel-obby-document
+;;
+
+(defclass rudel-obby-document (rudel-document)
+  ((id       :initarg  :id
+	     :type     integer
+	     :accessor rudel-id
+	     :documentation
+	     "The id of this document.
+The id has to be unique only with respect to the other documents
+owned by the owner.")
+   (owner-id :initarg  :owner-id
+	     :type     integer
+	     :documentation
+	     "")
+   (suffix   :initarg  :suffix
+	     :type     integer
+	     :documentation
+	     "A counter used to distinguish identically named
+documents."))
+  "Objects of the class rudel-obby-document represent shared
+documents in obby sessions.")
+
+(defmethod rudel-both-ids ((this rudel-obby-document))
+  "Return a list consisting of document and owner id of THIS document."
+  (with-slots ((doc-id :id) owner-id) this
+    (list owner-id doc-id)))
+
+(defmethod rudel-unique-name ((this rudel-obby-document))
+  "Generate a unique name for THIS based on the name and the suffix."
+  (with-slots (suffix) this
+    (concat (when (next-method-p)
+	      (call-next-method))
+	    (when (> suffix 1)
+	      (format "<%d>" suffix))))
+  )
+
+(defmethod eieio-speedbar-description ((this rudel-obby-document))
+  "Construct a description for from the name of document object THIS."
+  (format "Document %s" (object-name-string this)))
+
+(defmethod eieio-speedbar-object-buttonname ((this rudel-obby-document))
+  "Return a string to use as a speedbar button for OBJECT."
+  (with-slots (subscribed) this
+    (format "%-12s %s" (object-name-string this)
+	    (if subscribed "s" "-")))
+  )
+
+
+;;; Obby message functions
+;;
+
+(defun rudel-obby-replace-in-string (string replacements)
+  "Replace elements of REPLACEMENTS in STRING.
+REPLACEMENTS is a list of conses whose car is the pattern and
+whose cdr is the replacement for the pattern."
+  (let ((result string))
+    (dolist (replacement replacements)
+      (let ((from (car replacement))
+	    (to   (cdr replacement)))
+	(setq result (replace-regexp-in-string
+		      from to result nil t))))
+    result)
+  )
+
+(defun rudel-obby-escape-string (string)
+  "Replace meta characters in STRING with their escape sequences."
+  (rudel-obby-replace-in-string
+   string
+   '(("\\\\" . "\\b") ("\n" . "\\n") (":" . "\\d")))
+  )
+
+(defun rudel-obby-unescape-string (string)
+  "Replace escaped versions of obby meta characters in STRING with the actual meta characters."
+  (rudel-obby-replace-in-string
+   string
+   '(("\\\\n" . "\n") ("\\\\d" . ":") ("\\\\b" . "\\")))
+  )
+
+(defun rudel-obby-parse-color (color)
+  "Parse the obby color string COLOR into an Emacs color."
+  (let* ((color-numeric (string-to-number color 16))
+	 (color-string  (format "#%04X%04X%04X"
+				(lsh (logand #xff0000 color-numeric) -08)
+				(lsh (logand #x00ff00 color-numeric) -00)
+				(lsh (logand #x0000ff color-numeric)  08))))
+    color-string)
+  )
+
+(defun rudel-obby-format-color (color)
+  "Format the Emacs color COLOR as obby color string."
+  (multiple-value-bind (red green blue) (color-values color)
+    (format "%02x%02x%02x" (lsh red -8) (lsh green -8) (lsh blue -8))))
+
+(defun rudel-obby-assemble-message (name &rest arguments)
+  ""
+  (concat (mapconcat
+	   (lambda (part)
+	     (if (and (not (null part)) (stringp part))
+		 (rudel-obby-escape-string part)
+	       part))
+	   (cons name arguments) ":")
+	  "\n")
+  )
+
+(defun rudel-obby-parse-message (message)
+  "Split MESSAGE at `:' and unescape resulting parts.
+
+The terminating `\n' should be removed from MESSAGE before
+calling this function."
+  (mapcar #'rudel-obby-unescape-string (split-string message ":")))
+
+(defun rudel-obby-send (socket name arguments)
+  "Send an obby message NAME with arguments ARGUMENTS through SOCKET."
+  ;; First, assemble the message string.
+  (let ((message (apply #'rudel-obby-assemble-message
+			name arguments)))
+    (if (>= (length message) rudel-obby-long-message-threshold)
+	;; For huge messages, chunk the message data and transmit the
+	;; chunks
+	(let ((total    (/ (length message)
+			   rudel-obby-long-message-chunk-size))
+	      (current  0)
+	      (reporter (make-progress-reporter "Sending data " 0.0 1.0)))
+	  (rudel-loop-chunks message chunk rudel-obby-long-message-chunk-size
+	    (progress-reporter-update reporter (/ (float current) total))
+	    (process-send-string socket chunk)
+	    (incf current))
+	  (progress-reporter-done reporter))
+      ;; Send small messages in one chunk
+      (process-send-string socket message)))
+  )
+
+
+;;; Autoloading
+;;
+
+;;;###autoload
+(rudel-add-backend (rudel-backend-get-factory 'protocol)
+		   'obby 'rudel-obby-backend)
+
+;;;###autoload
+(eval-after-load 'rudel-zeroconf
+  '(rudel-zeroconf-register-service "_lobby._tcp" 'obby))
+
+(provide 'rudel-obby)
+;;; rudel-obby.el ends here