Pidgin is a free and open-source chat client which supports AIM, Google Talk, ICQ, XMPP protocols.

Empathy is an instant messaging (IM) and voice over IP (VoIP) client which supports text, voice, video, file transfers, and inter-application communication ov…

Instantbird is a cross-platform instant messaging client based on Mozillas XULRunner and the open source library libpurple used in Pidgin.

Tkabber is a GPL instant messaging client for the XMPP protocol which uses the Tk toolkit for the GUI.

Trillian is a proprietary multiprotocol instant messaging application.

Kopete is a multi-protocol, free software instant messaging client released as part of the KDE Software Compilation. Although it can run in numerous environme…

qutIM is free and open-source multiprotocol (ICQ, Jabber, Mail.Ru, IRC, VKontakte) instant messenger.