Adium is a free and open source instant messaging application for Mac OS X, written using Mac OS Xs Cocoa API, released under the GNU GPL and developed by the Adium team.
The goal of Gajim is to provide a full featured and easy to use Jabber client. Gajim works nicely with GNOME, but does not require it to run. It is released under the GNU General Public License.
amsn is a free open source msn messenger clone. amsn attempts to emulate the look and feel of windows live messenger, and supports many of its features.
Alternativein is a new approach to finding good application.
Just type what software you want to change and browse great alternatives,
based on our great community recommendations.