Pidgin

Miranda IM is the smaller, faster, easier instant messenger with support for multiple protocols. Designed from the ground-up to be resource efficient while still providing a rich feature set, Miranda …

Jitsi (previously SIP Communicator) is an audio/video and chat communicator that supports protocols such as SIP, XMPP/Jabber, AIM/ICQ, Windows Live, Yahoo! and many other useful features. Jitsi is...

HexChat is a fork of XChat with bug fixes and new features.. It's free and a continuation of the XChat-WDK project.

Psi is an instant messaging application for Windows, Linux, and Mac OS X that connects to the free, open Jabber IM network (also known as XMPP). Localized versions of Psi …

emesene is a chat program that allows you to connect to different networks like MSN, Gtalk, Facebook chat, Jabber and others.

aMSN is a free open source MSN Messenger clone. aMSN attempts to emulate the look and feel of Windows Live Messenger, and supports many of its features. Offline Messaging Voice …

The goal of Gajim is to provide a full featured and easy to use Jabber client. Gajim works nicely with GNOME, but does not require it to run. It is …

qutIM - free open-source multiprotocol ( ICQ, Jabber/ GTalk/Ya.Online/LiveJournal.com, Mail.Ru, IRC ) instant messenger for Windows, Linux, MacOS X, OS/2, Symbian, Maemo/MeeGo, Solaris and *BSD.

KVIrc is a free portable IRC client based on the excellent Qt GUI toolkit. KVirc is being written by Szymon Stefanek and the KVIrc Development Team with the contribution of …

Instantbird is an instant messaging client based on Mozilla XULRunner and the open source library libpurple created by the software developers of Pidgin. Instantbird is free software available under the …

Kadu is an open source Jabber/XMPP and Gadu-Gadu instant messenger client for Linux, *BSD, Mac and Windows.

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

TorChat is a peer to peer instant messenger with a completely decentralized design, built on top of Tor's location hidden services, giving you extremely strong anonymity while being very easy …

Miranda New Generation is a successor of a popular multi-protocol instant messaging client for Windows - Miranda IM. Very light on system resources and extremely fast.

Spark is an Open Source, cross-platform IM client optimized for businesses and organizations. It features built-in support for group chat, telephony integration, and strong security. It also offers a great...

Tkabber is a Free and Open Source client for the Jabber instant messaging system. Its writen in Tcl/Tk, and works on many platforms (tested on Linux, FreeBSD, NetBSD, Solaris, MacOS …

Nettalk is a powerful but easy to use free (open source) IRC-client for Windows. The smart user interface is based on Windows standards, so it is easy to get used …

Pandion is an open source instant messaging client for XMPP networks. Keep in touch with friends or collaborate with colleagues using Pandion instant messenger. Pandion is free software and uses …

An IRC client for the Windows desktop which follows the Metro design guidelines.

Crossplatform Jabber client. The core program is just a plugin loader - all functionality is made available via plugins. This enforces modularity and ensures well defined component interaction via interfaces.

Subway is a web-based IRC client with a multi-user backend and a JavaScript-heavy UI. Frontend/backend communication is done with websockets (or best available fallback where not available). The backend...

Facebook Chat IM is a Desktop Messenger for Facebook. With it you can chat with all your Facebook friends directly from your Desktop. It has a simple and easy to …

OneTeam – simple, secure and easy to use. OneTeam is a versatile instant messaging client that is very intuitive to use. Even people who are new to instant messaging will …