Jitsi
Open Source
Jitsi (formerly SIP Communicator) is a free and open source multiplatform voice (VoIP), videoconferencing and instant messaging application.
Zulip
Open Source
Zulip is a chat and collaborative software.
Tkabber
Open Source
Tkabber is a GPL instant messaging client for the XMPP protocol which uses the Tk toolkit for the GUI.
Wire
Free
Wire is a cross-platform, encrypted instant messaging client created by Wire Swiss. It is available for iOS, Android, Linux, Windows, macOS and Web browser cl…
QuteCom
Open Source
QuteCom (WengoPhone) is a free-software SIP-compliant VoIP client.
YakYak
Open Source
YakYak is a desktop chat client for Google Hangouts.
