Pidgin

Miranda IM is the smaller, faster, easier instant messenger with support for multiple protocols. Designed from the ground-up to be resource efficient while still providing a rich feature set, Miranda …

Meebo is integrated, all-in-one instant messaging (IM client) that connects you with your friends everywhere. It supports a large number of popular servicesand connects you to MSN, Yahoo, AOL/AIM, MySpace, …

emesene is a chat program that allows you to connect to different networks like MSN, Gtalk, Facebook chat, Jabber and others.

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 …

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 …

Miranda New Generation is a successor of a popular multi-protocol instant messaging client for Windows - Miranda IM. Very light on system resources and extremely fast.

Tkabber is a Free and Open Source client for the Jabber instant messaging system. Its writen in Tcl/Tk, and works on many platforms (tested on Linux, FreeBSD, NetBSD, Solaris, MacOS …

Sim-IM is a multiple protocol instant messenger for MS Windows, GNU/Linux, FreeBSD. Sim-IM supports Jabber/XMPP, Google Talk, ICQ and AIM (Oscar), Yahoo! Messenger and Microsoft Messenger (MSN) protocols....