
Thunderbird
thunderbird is a free, open source, cross-platform e-mail, news and instant messaging client. the project strategy is modeled after mozilla firefox.
WeeChat is a fast, light and extensible chat client. It runs on many platforms (including Linux, BSD and Mac OS).
weechat is a fast, light and extensible chat client. it runs on many platforms (including linux, bsd and mac os).
weechat is: modular: a lightweight core with plugins around multiprotocols: irc and jabber (other soon) extensible: c plugins and scripts (perl, python, ruby, lua, tcl and scheme) free software: released under gplv3 license fully documented: user's guide, api, faq,.. translated in many languages
source code : https://github.com/eirikb/weecloud
Extensible by Plugins/Extensions Multiple protocols Modular System Command line interface
Productivity Developer Tools Social
extensible chat-clients im-client irc jabber multi-protocol xmpp modular-system command-line-interface chat-xfce