Psi is a free instant messaging application designed for the Jabber IM network (including Google Talk). Fast and lightweight, Psi is fully open-source and compatible with Windows, Linux, and Mac OS X.
Whether you use Windows, Linux, or a Mac, Psi is right at home on your desktop. From the system tray icon on Windows to the dock badges on Mac OS X, Psi takes advantage of each operating system’s unique features and appearance to provide a first-class IM experience on almost any computer.
Download Microsoft Windows | Mac OS X |Source Code