A group is a collection of objects sharing common application semantics. From this point of view, we can think that the groupware, which enables many users to share their tasks with others, is an application fo the group concept. In this thesis, we propose a new set of group system interface for the groupware development. A groupware should provide three functions : communication, collaboration, and coordinateion. A group supports the communication and coordination functions hiding the details of network and heterogeneity of underlying system. We developed a toolkit library providing group interfaces for collaboration and the information sharing mechanism. An implementation of the collaboration group on OSF/DCE is also described.
