From Adam Iser:
The Adium team is proud to present to you Adium X, a multiple-protocol instant-messaging client. This is a culmination of a yearlong rewrite of Adium, which now utilizes Libgaim (the core part of GAIM) to connect to multiple protocols, and also is based on a new plug-in architecture. Partial address-book integration, cool-looking tabs, multiple protocols for instant messaging, and a compact contact list are some of the many features of the new Adium X. Some core features include support for AIM, Yahoo, MSN, Jabber, Trepia, Napster, and Gadu-Gadu; unlimited accounts; as many names on as many services as you want; draggable tabs; any number of tabs in any number of windows; highly customizable yet intuitive preferences; address-book integration; iTunes and other AppleScript substitution buddy icons and away messages in AIM; and the beginnings of file-transfer support for AIM, Yahoo, and Jabber.
What's new in this version:
Expanded connection capabilities.