Google chat

Google have launched Google Talk. It uses the Jabber protocol. Unlike MSN, AIM and the like, Jabber is an open standard, a series of RFCs that anyone is free to implement. If you are running OS X Tiger, iChat is a Jabber client. There’s also the open source OS X instant messenger Adium. Linux users have Kopete and Gaim. Windows users have Miranda, Exodus, Psi, Trillian Pro, and many more.