Update: Unfortunately Ebby is only compatible with version 0.3 of Gobby, and even that compatibility leaves a bit to be desired. (See bug mentioned above.) I would love to fix this, but achieving compatibility with version 0.4 would be a waste of time as the Gobby developers have stated their intent to change the protocol again with the next version. Hopefully the protocol will stabilize eventually, and at that point I would like to continue development, but right now things are kind of at a standstill.
Ebby is an implementation of the Obby protocol in Emacs Lisp. Obby is a free collaborative editing protocol supporting multiple documents in one session and a multi-user chat. Currently Gobby is the only other client that supports the protocol.
Ebby supports two-way buffer updating when connected to Gobby as a server. (Supports version 0.3 of the Obby protocol.) There is no support for distinguishing users by color... yet.
M-x ebby, enter connection infoM-x ebby-subscribe, enter.ebby-subscribe will default to document "1 1", which is the first document. To access the second document created by the first user, enter "1 2" when M-x ebby-subscribe asks you for a document ID.
If you don't have Gobby, you should get it. (version 0.3) If you don't want to, you can try connecting to technomancy.us:6522, though I don't have my Gobby server running 100% of the time.
Get it from my DotFiles
To try it out, open it in a buffer and type M-x eval-buffer. To permanently install it, save it to your Emacs path and put (require 'ebby) in your .emacs file.
The biggest problem is that the history is not stored properly, so conflicting edits may not be merged correctly in high-latency situations. You shouldn't run into any problems with two or three users on a local connection, but collaborations over long distances may encounter unpredictable results.
Feel free to download and tinker. Patches are welcome. (Well, good patches...) Please see EditingWiki to see how to change this page. (Due to spammers I've had to add a step.)