TracChat provides a "Chat" tab in the Trac interface that allows to communicate with each other through a Jabber groupchat.
The advantage of this approach is that ordinary Jabber clients such as Psi can also be used in the chat. Also logging tools such as Bandersnatch could be used to make conversations available later.
Download the latest tarball (2007-10-05): tracchat-0.6.tar.gz
Browse the latest source code
Get the source code from Mercurial
$ hg clone http://delx.net.au/hg/tracchat
Bug reports and comments go to James Bunton