Instant Messaging System, similar to ICQ or AIM, but yet far different. It is open-source, absolutely free, simple, fast, extensible, modularized, cross platform, and created with the future in mind. Jabber has been designed from the ground up to serve the needs of the end user, satisfy business demands, and maintain compatibility with other messaging systems.
Two versions - downloable (for win95/98/NT) and online (for win 3.1/Mac/Unix and other platforms) - no download necessary. Alerts for new messages in your Yahoo! Mail or Yahoo! Personals account and for upcoming meetings in Yahoo! Calendar. You can also get news, sport scores, and stock quotes.