This paper outlines CLEW (collaborative learning environment for the Web). The project combines MUD (Multi-User Dimension), workflow, VRML (Virtual Reality Modeling Language) and educational concepts like constructivism in a learning environment where students actively participate in the learning process. The MUD shapes the environment structure. The workflow system allows the execution and coordination of the course activities. The VRML establishes the presentation format of the courses' virtual worlds. Finally, the educational concepts influence the way the didactic material is published. Topics discussed include: the educational background that guides the environment; the environment components, including the participants, regions, and objects; the six layers of the system architecture--presentation, application, management and control, adaptation, external services, and data; the course development, including structuring a course, and the participant's perspective; and future plans. A diagram of the system architecture is included. Contains 20 references. (Author/DLS)