IRC built-in. Multi-protocol friendly for module authors.

Shipped-by-default Perl scripting with a wide range of available extensions.

Integrates into the UNIX stack: Your window manager, your terminal emulator, your remote connection, your terminal multiplexer, your IRC bouncer, your IRC adapter.

Irssi is free software licensed under the GPLv2, available for Linux, BSD, Solaris, Apple, Cygwin, …