Appl
e previewed Mac OS X 10.2 today, and one of the features introduced is iChat, a system-wide IM client to be built into Mac OS X 10.2. Code named "Jaguar," Mac OS X 10.2 is scheduled to be released in the "late summer." iChat is based on AIM, AOL's very popular instant messaging client, and Apple worked with the company to develop iChat.
Check It Out: Apple Previews iChat Instant Messaging System