This paper presents an overview of Virtual Relaity (VR) system technology and its application within the Fraunhofer Demonstration Centre for VR at IGD in Darmstadt. First we discuss the essential dimension in virtual environments (VE), namely the simulation, the interaction and the presentation dimension. A brief reflection on VR devices and systems ist followed by an introduction of the VR Demonstration Centre, its goals and infrastructure. Various pre-processing and editing tools are introduced and their benfit for the realization of efficient and high-quality virtual worlds are highlighted. The Virtual Reality toolkit VirtualDesign of IGD is explained. A broad range of applications demonstrate the usability of Virtual Reality technology, which enables new dimensions in computer-supported applications.