Adium is a free IM client for Mac OS X. It supports AIM, MSN, Jabber, ICQ and Yahoo protocols and has a very Mac friendly interface.

So far everything has worked well for me with the exception of a ICQ password hiccup from Keychain. After having tried Fire, Adium is simply easier to understand and get started with. Since Adium is based on LibGaim, don’t expect any video / audio chat features to be implemented soon. This is the problem with all “unofficial” clients. Why can’t MSN just make an iSight compatible Messenger client already? Final word: good stuff, easy to use, free!