: The ubiquitous nature of the World Wide Web provides the ideal framework for spontaneous collaboration of disjoint users. However, for Computer Supported Collaborative Work (CSCW) to actually function in the Web, added coordination is needed. Firstly, a globally consistent state of the data must be maintained through some extended transaction concept. This is typically the task of a database system. Secondly, a suitable engine at the client side must permit setting a focus on the shared data. Any concurrent activities of other users which happen to stretch into a user's viewport must also be made visible. Finally, the client must provide mechanisms for moving among the data (objects), for concurrency awareness, and for manipulation of the data. Clearly, such an approach goes beyond the groupware solutions which are based on whiteboard and telepointer methaphers, as they seldom allow immersion into a structured object space. Here, we present a complete and detailed descrip...