Pidgin is described as 'Chat program which lets you log into accounts on multiple chat networks simultaneously. This means that you can be chatting with friends on XMPP and sitting in an IRC channel at the same time' and is a leading instant messenger in the social & communications category. There are more than 100 alternatives to Pidgin for a variety of platforms, including Linux, Mac, Windows, Web-based and BSD apps. The best Pidgin alternative is Element. It's not free, so if you're looking for a free alternative, you could try Element or Matrix. Other great apps like Pidgin are Jami, Beeper, SeaMonkey and Element X.
Ayttm is an instant messaging (aka chat) client that provides all-in-one chat functionality for several major instant messaging services from one simple program. Ayttm "Contacts" allow you to refer to several accounts of the same person from a single contact name...
Vacuum-IM is a 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.
Glowing Bear is a sleek, modern web frontend that securely connects to a running instance of WeeChat using its built-in relay protocol. It relies on WeeChat to do all the heavy lifting and then provides some nice features on top of that, like...
Commandline XMPP Client. Profanity was originally written for two main reasons. Firstly, the author wanted something similar to Irssi, but with a focus on XMPP for use in his workplace. Secondly, it was a bit of fun and a learning exercise.
Kadu is an open source Jabber/XMPP and Gadu-Gadu instant messenger client for Linux, *BSD, Mac and Windows.
emesene is an instant messenger capable of connecting to various networks and utilizing different graphical toolkits. Currently msn and jabber are supported through papyon and xmppy, which allows emesene to connect to various IM services such as GTalk, Facebook Chat, etc.
naim is a console client for AOL Instant Messenger (AIM), AOL I Seek You (ICQ), Internet Relay Chat (IRC), and The lily CMC.
R&Q is a little instant messaging client for the ICQ protocol, fork of Rejetto's &RQ. It is simple, fast, takes a little more than 1 MB disk space and doesn't need setup.
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