Virtual objects and control tools are located on a real 'workbench' (fig. 1). The objects, displayed as computer-generated stereo-images are projected onto the surface of the workbench. This setting corresponds to the actual work situation m an architect's office, in surgery environments, etc.

A guide uses the virtual working environment while several observers can watch events through stereo shutter glasses (fig. 2). The participants operate within a non-immersive virtual environment. Depending on the application, various input and output modules can be integrated, such as motion, gesture and voice recognitions systems, which characterize the general trend away from the classical human-machine interface. Several guides can work together in similar environments either locally or by using broadband communication networks. A responsive environment, consisting of powerful graphic workstations, tracking systems, cameras, projector, and microphones, replaces the traditional multimedia desktop workstation.
Two scenarios have been realized so far: design and discussion process in architecture, landscape and environment planning, and surgery planning and non-sequential medical training. (Wolfgang Krüger)