Adium is a free and open source instant messaging application for OS X, written using OS X's Cocoa API, released under the GNU GPL and developed by the Adium team. Based on the libpurple protocol library, Adium can connect you to any number of messaging accounts on any combination of supported messaging services and then chat with other people using those services.
Adium X 0.88 up to Adium 1.4.5 are Universal applications which run natively on both PowerPC- and Intel-based Macintosh computers. Adium 1.5 and up require an Intel based computer.
See our Supported OS Policy for more information.
See our own wiki for ways you can contribute to Adium.