Bistri

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 …

Kopete is an instant messenger supporting AIM, ICQ, MSN, Yahoo, Jabber, IRC, Gadu-Gadu, Novell GroupWise Messenger, and more. It is designed to be a flexible and extensible multi-protocol system suitable …

Psi is an instant messaging application for Windows, Linux, and Mac OS X that connects to the free, open Jabber IM network (also known as XMPP). Localized versions of Psi …

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. Offline Messaging Voice …

qutIM - free open-source multiprotocol ( ICQ, Jabber/ GTalk/Ya.Online/LiveJournal.com, Mail.Ru, IRC ) instant messenger for Windows, Linux, MacOS X, OS/2, Symbian, Maemo/MeeGo, Solaris and *BSD.

Instantbird is an instant messaging client based on Mozilla XULRunner and the open source library libpurple created by the software developers of Pidgin. Instantbird is free software available under the …

Kadu is an open source Jabber/XMPP and Gadu-Gadu instant messenger client for Linux, *BSD, Mac and Windows.

Finch is a console-based IM program that lets you sign on to AIM, Jabber, MSN, IRC, Yahoo!, and other IM networks. It runs on Unixes. It uses GLib and ncurses.

Spaz is a Twitter client for users who value free, open-source software, attractive design, and customizability

Coccinella is a free and open-source cross-platform instant messaging client with a built-in whiteboard for improved collaboration with other people.

GyachE Improved (GyachI) is a fork from Gyach Enhanced Yahoo! client for Linux operating systems. This Yahoo! client supports almost all of the features you would expect to find on …

Gabtastik lets you keep chat sessions open on your desktop outside of your regular web browser, using minimal screen real estate and system memory. Gabtastik also lets you specify window …