Weechat

WeeChat is a lightweight, fast chat client that runs on GNU/Linux, BSD, GNU/Hurd, Haiku, macOS and Windows environments. Its core is intentionally small, while optional plugins—such as a full‑featured IRC implementation—can be loaded or unloaded independently, allowing support of multiple protocols without bloating the program.

The client offers extensive customization through a large set of options and supports scripting in several languages, including Python, Perl, Ruby, Lua, Tcl, Scheme, JavaScript and PHP, with a built‑in script manager. Users can tailor the interface with split windows, configurable bars, 256‑color themes and smart filtering, and remote connections are possible via browser, smartphone, GUI clients, Emacs or other WeeChat instances.

All components are released under GPL‑3.0, making the software free, self‑hostable and free of subscription requirements. Documentation is comprehensive and translated into multiple languages, and the project maintains a stable release track with regular updates.