COVEN (Collaborative Virtual Environments) is a European project that seeks to develop a comprehensive approach to the issues in the development of collaborative virtual environment (CVE) technology. COVEN brings together twelve academic and industrial partners with a wide range of expertise in CSCW, networked VR, computer graphics, human factors, HCI, and telecommunications infrastructures. After two years of work, we are presenting the main features of our approach and results, our driving applications, the main components of our technical investigations, and our experimental activities. With different citizen and professional application scenarios as driving forces, COVEN is exploring the requirements and supporting techniques for collaborative interaction in scalable CVEs. Technical results are being integrated in an enriched networked VR platform based on the dVS and DIVE systems. Taking advantage of a dedicated Europe-wide ISDN and ATM network infrastructure, a large component of the project is a trial and experimentation activity that should allow a comprehensive understanding of the network requirements of these systems as well as their usability issues and human factors aspects.