This is a Qt GUI client for the Lichat protocol. It offers multiple connections, customisable looks, private conversations, user muting, autojoining, tray support, desktop notifications, highlighting, and so forth.
Load Lionchat and start it up:
(ql:quickload :lionchat) (lionchat:start)
You can also build a standalone binary like so:
(asdf:operate :program-op :lionchat)
Here's some screenshots to pique your interest: