pymucl is a MUC client for telepathy, especially aimed at Maemo 5. There are MUC clients in the repositories but none of them uses the accounts already available on Maemo.
Secure video calls, conferencing, chat, desktop sharing, file transfer, support for your favorite OS, and IM network. All this, and more, in Jitsi - the most complete and advanced open source communicator.
Psi+ is a cross-platform powerful Jabber client (Qt, C++) designed for the Jabber power users.
Brings all XMPP wonders to Drupal, interacting with user via javascript and plain old HTTP. Strophe javascript library is used for handling all javascript gears
iJab is an Ajax-based web based instant messaging program for XMPP/Jabber. It is free software