ICQ

Trillian is a proprietary multiprotocol instant messaging application for Windows, Mac OS X, Android, iOS, BlackBerry OS, and the Web, created by Cerulean Studios. It can connect to multiple IM …

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, …

Empathy is a messaging program which supports text, voice, and video chat and file transfers over many different protocols. You can tell it about your accounts on all those services …

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 …

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.

BitlBee is a IRC gateway program for MSN, ICQ, AIM and XMPP (Jabber, Google Talk, Facebook). It acts as a IRC server, creates a IRC "channel" with all your contacts …

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

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....