iChat is Apple's instant messaging application. First introduced in 2002, it has now been replaced by Messages.
iChat is Apple's built-in instant messaging application for OS X. It supports XMPP/Jabber, AIM OSCAR, as well as Bonjour discovery. It also supports video chatting, audio chatting, and screen sharing. It features Address Book and Mail integration for contacts. As of February 2012, iChat has been discontinued in favor of messages.