Hyper - Extensible, cross-platform terminal built on open web standards.
HexChat - HexChat is a fork of XChat with bug fixes and new features.
Windows Terminal - A new command line interface for Windows machines
irssi - Irssi is a terminal based IRC client for UNIX systems.
Bidbar - Save and run Terminal commands from the Mac menu bar
Adium - Adium is a free instant messaging application for Mac OS X that can connect to AIM, MSN, Jabber, Yahoo, and more.