Adium is an Open source multi-protocol instant messaging client for Mac OS X, supports MSN, Jabber, Yahoo! and other networks.

Bit Chat is a secure, peer-to-peer, open source instant messenger with end-to-end encryption.

Coccinella is a free and open-source cross-platform client for the XMPP/Jabber-instant messaging-protocol.

CSipSimple is a Voice over Internet Protocol (VoIP) application for Google Android operating system using the Session Initiation Protocol (SIP).

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

Franz is a free messaging app /former emperor of Austria, that combines chat & messaging services into one application.

appear.in provides one-click video conferences right in your browser without requiring PIN codes or additional software.

Blink is the best real-time communications client using the SIP protocol.

Conversations is an open source XMPP/Jabber client for the Android platform.

Disa is your new messaging hub. Conversations from different services can seamlessly be joined together, or disbanded within seconds.

Facebook Messenger is the official Facebook app that lets you have text conversations with all of your friends on the popular social network.

Fring connects with Skype, MSN Messenger, ICQ and Google Talk from your iPhone.