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

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…

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

Tox is a peer-to-peer instant-messaging and video-calling protocol that offers end-to-end encryption.

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

Gajim is an instant messaging client for the XMPP protocol which uses the GTK+ toolkit.

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