Active Worlds Browser - 2.1 build 295 

Active Worlds Browser is real-time chat software that can be used from the World Wide Web. It has a 3D-type interface where everyone adopts an avatar, and, unlike using chat rooms, you point-and-click to walk closer to different groups. There are many "worlds" available where you can go to chat with different people.

Teamwave Workplace - 4.2 

Much more than just a chat room, Teamwave Workplace allows groups working on a project in different areas, floors, cities or even countries to stay in touch during the lifespan of a project. Features include virtual rooms, concept maps, bulletin boards, calendars, databases, real-time chat, whiteboard and more. Communicating with the members of your project team has never been easier!