**[http://www.g1m0.se/macirssi/ MacIrssi], a good IRC client that doesn't have as many features as X-Chat Aqua. Basically a GUI for IRSSI.
** [http://colloquy.info/ Colloquy], a native Aqua IRC client that integrates well into OS X and offers a rich featureset.
**[http://homepage.mac.com/philrobin/conversation/ Conversation]
*Cross-platform
**[http://www.hacksrus.com/~ginda/chatzilla/ ChatZilla], an IRC extension for Firefox.