lightIRC - lightIRC is a fast, free, Flash-based IRC Client. It supports webcams with an extension!
HexChat - HexChat is a fork of XChat with bug fixes and new features.
LiveAgent - LiveAgent is a fully-featured web-based live chat and help desk software. It harnesses the power of a universal inbox, real-time live chat, built-in call center, and a robust customer service portal. Start your free 1 month trial today!
IRCCloud - IRCCloud is a modern IRC client that keeps you connected, with none of the baggage. Stay synced and notified wherever you are with our web and mobile apps.
uhChat - uhChat is a chat window software that can be integrated into any website.
irssi - Irssi is a terminal based IRC client for UNIX systems.