An Internet-based distributed multi-user VR system, developed by researchers at the Swedish Institute of Computer Science since 1991. http://www.sics.se/dive/
A guide to online virtual worlds with a focus on social interaction. Basic info, visitor ratings, reviews and helpful links for each program. http://www.virtualworldsreview.com/
A software infrastructure for distributed object-oriented programming. The primary application for VOS is a multiuser virtual environment run by many interconnected clients. http://interreality.org
3D chat world. Customizable avatars with facial expression. Users can chat, build and furnish a house, listen to music, share files. Can be integrated with external tools. http://www.moove.com/