Kadu!

Facebook Messenger is a faster way to message. Reach friends right on their phones, get and send messages fast, message everyone at once and more.

Adium is a free and open source instant messaging application for Mac OS X, written using Mac OS Xs Cocoa API, released under the GNU GPL and developed by the Adium team. Based on the libpurple protocol library, Adium can connect you to any number of messaging accounts on any combination of supported messaging services and then chat with other people using those services.

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 includes support for AIM, Jabber, ICQ, IRC, MSN, Yahoo, Gadu-Gadu and more. Additionally, with the choice of hundreds of plugins, icons, sounds and other content.

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.

Chat everywhere! IM+ is the most widely used mobile IM app! Connect all-in-one to MSN, Yahoo!, Google Talk, AIM, Jabber, ICQ, Facebook, MySpace and Twitter on ALL popular mobile platforms.

Private instant messaging via secure, distributed technology.

A simple & beautiful app for Facebook Messenger.Chat without distractions on any Operating System.

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.

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

The Swift project was founded by Remko Tronçon and Kevin Smith, both co-authors of XMPP: The Definitive Guide and long-time members of the XMPP community, in an effort to create a better messaging client for users who want or need to access servers running with the standard XMPP protocols and who want a client that’s easy to use, responsive and unobtrusive. Since then the Swift ecosystem of software has grown to include XMPP libraries for multiple languages/platforms and assorted smaller XMPP tools. »

Jabber client for Android.

Sim-IM, Simple Instant Messenger, is a multiple protocol instant messenger for MS Windows, GNU/Linux, FreeBSD. Sim-IM supports Jabber/XMPP, Google Talk, ICQ and AIM (Oscar), Yahoo! Messenger and Microsoft Messenger (MSN)protocols. Sim-IM is a free software, licensed under the GNU General Public License (GPL). Sim-IM is based on the Qt library, and can be built with KDE-support option.