As I told in an earlier post, MacOS X 10.4 aka Tiger feature Jabber compatibilty in iChat. I found the Jabber FAQ on MacOS X Tiger for those who want to make the switch. I'd really love to see the Mac users switcher over to Jabber.

Note that you don't need MacOS X 10.4 to connect to Jabber. There are a lot of Jabber client on Mac.