The Virtual Reality Modeling Language is the international standard for interactive 3D on the Web. It has been superseded by X3D, the largely back-compatible successor to VRML. VRML Browser plugins allow you to view VRML content through your web browser.
Multi-User VRML
One of the dreams which has driven the development of 3D on the Internet is that of shared, multi-user environments with communications between users. This dream is now being met in reality by a variety of technologies, some proprietary and some portable.