Irssi

Irssi is a terminal based IRC client for UNIX-based operating systems. Irssi comes with IRC built-in and is multi-protocol friendly for module authors, it also support integration with SILC and ICB protocols via plugins. The application easily integrates with your window manager, your terminal emulator, your remote connection, your terminal multiplexer, your IRC bouncer and your IRC adapter. Allowing you to use Irssi virtually everywher throughout your system. Irssi is free software licensed under the GPLv2, available for macOS, Linux, BSD, Solaris, and Cygwin.