w00t for quakenet - all my UT fragging was done on that. Devs invariably try and recreate the wheel with chat clients. In MMO games its an epic fail to not make comms the VITAL feature needed above graphics. I have yet to play a mmorts thats got this right yet and my advice is, unless you have the new WoW type defining creation to bring to the feast - dont bother. Integrate irc,skype or ventrillo as a thirdparty provider (ie some experts) and let your players communicate.
All else tried has failed and largely not even failed on a reasonable scale - they usually take us back to the nineties minimum.
TIP OF THE DAY – If you're being chased by a police dog, try not to go through a tunnel, then on to a little seesaw, then jump through a hoop of fire. They're trained for that.