centericq is a text mode menu- and window-driven IM interface that supports the ICQ2000, Yahoo!, AIM, IRC, MSN, Gadu-Gadu, and Jabber protocols. It allows you to send, receive, and forward messages, URLs, SMSes (both through the ICQ server and email gateways supported by Mirabilis), contacts, and email express messages, and it has many other useful features. An internal RSS reader and a LiveJournal client are also provided.
KVirc is a Visual Internet Relay Chat Client based on the Qt library. Features include a MDI user interface, drag & drop, built-in scripting language (aliases, popups and events), customizable backgrounds and colours, DCC (chat, send with resume, voice), CTCP functions, mIRC colour support with preview, notify list, online help and configurable logging.
Manhattan is a Web-based course management system. It includes its own private email system, a variety of discussion groups, assignments, surveys, and grades modules, live chat, facilities for delivering multimedia, and more. Designed for asynchronous Web-based distance learning, Manhattan can also be used to add an online dimension to traditional courses. Manhattan is fully documented.
Chat Everywhere is a simple and powerful chat client/server system for Web pages. It supports channel administration, IRC-like commands, connection filtering, extensive logging, and much more. The client works in any Web browser that can run Java applets. The server is written in POSIX-compliant C and runs on any kind of Unix.
The Interverse is the evolution and combination of the Web, chat, instant messaging (IM), and voice communication. It is not just a graphical user interface (GUI), but an immersive user interface (IUI). The Interverse is a virtual universe running on top of the Internet. It uses the Crystal Space 3D engine to render the user's view of the world.