Open Source

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

Open Source

Jitsi (formerly SIP Communicator) is a free and open source multiplatform voice (VoIP), videoconferencing and instant messaging application.

Miranda IM

Open Source

Miranda IM is an open source multiprotocol instant messaging application, designed for Microsoft Windows.

Ring

Open Source

Ring (SFLphone) is an open-source SIP-compatible softphone and instant messenger for Linux, Microsoft Windows, OS X and Android.

Gajim

Open Source

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

Quassel IRC

Open Source

Quassel IRC, or Quassel, is a graphical, distributed, cross-platform IRC client.

Matrix.org

Open Source

Matrix is an open protocol for real-time communication. It is designed to allow users with accounts at one communications service provider to communicate with…

qutIM

Open Source

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

Kadu

Open Source

Kadu is a free and open source multi-platform instant messaging client that supports Gadu-Gadu, XMPP IM networks and other services based on XMPP like Google …

Coccinella

Open Source

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

Tkabber

Open Source

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

Trillian

Freemium

Trillian is a proprietary multiprotocol instant messaging application.

Digsby

Open Source

Digsby provides you with IM, email and Social networks in one easy to use application.

Psi

Open Source

Psi is a free instant messaging application designed for the XMPP network (including Google Talk). Fast and lightweight, Psi is fully open-source and compatib…

ICQ

Free

ICQ is an open source instant messaging software.

Miranda NG

Open Source

Miranda NG is a successor of Miranda IM, a popular multi-protocol instant messaging client for Windows.

Instantbird

Open Source

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

Spark

Open Source

Apache Spark is an open-source cluster-computing framework.

Psi+

Open Source

Psi is a cross-platform powerful XMPP/Jabber client (Qt, C++) designed for the Jabber power users. Psi+ is a development branch of Psi IM XMPP/Jabber client.