Chop Chop, Jabber is OpenSRF's custom lighweight Jabber server. It's designed with speed and simplicity in mind, and thus boasts roughly 2% of the XMPP (http://www.xmpp.org/) feature set. What it provides is fast XMPP message routing with little extra logic to support the wealth of XMPP options.
Highlights of Chop Chop
Support client logins over TCP/IP and Unix sockets. Unix sockets provide a fast local interface to the server when both client and server are running on the same machine.
Standard XMPP login sessions. Note, however, that the current server allows any client to login regardless of username, password, or domain. If you're planning on running Chop Chop, it must be run in a private network or anyone, anywhere can login to the server.
Standard Jabber/XMPP message routing.
Standard error message when sending messages to users that are not logged in
The source for Chop Chop can be found at: http://open-ils.org/cgi-bin/viewcvs.cgi/ILS/OpenSRF/src/jserver/
See Compiling Chop Chop and Running Chop Chop