WeeChat is a fast, light and extensible chat client. It runs on many platforms (including Linux, BSD and Mac OS).
- modular: a lightweight core with plugins around
- multi-protocols: 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
Development is very active, and bug fixes are very fast!