CLALN01Project teams have become an important element in teaching informatics. Web-based groupware systems are increasingly used in such educational settings. This kind of educational teamwork and computational support is comparable to project work observed in industrial settings. In our paper, we present the design principles for a web- based system called 'CommSy', an abbreviation for Community System, which has been successfully applied in a number of educational projects. We outline the didactic aims leading to the particular design of the system as well as the specific support the system provides. Further, we provide some anecdotal evidence as to how the design principles have helped the project teams and whether or not the teams felt the system adhered to the principles discussed.