Textual Alternatives

Irssi is a terminal based IRC client for UNIX systems.

mIRC: Internet Relay Chat client

HexChat is a fork of XChat with bug fixes and new features.

KVIrc is a free portable IRC client based on the excellent Qt GUI toolkit.

Pidgin is an easy to use and free chat client used by millions. Connect to AIM, MSN, Yahoo, and more chat networks all at once.

A hand-crafted IRC client that you can enjoy. Designed to be used easily and freely.

WeeChat is a fast, light and extensible chat client.

Traditionally, chat clients on the Mac have been anything but glamorous.

LimeChat is an IRC client for Windows, Mac OS X and iOS. Features

Adium is a free instant messaging application for Mac OS X that can connect to AIM, MSN, Jabber, Yahoo, and more.

AdiIRC - Free IRC Client

Quassel IRC is a modern, cross-platform, distributed IRC client based on the Qt4 framework.

An IRC-like chatroom hosted on ZeroNet, a distributed network.