Abstract: Group Communication Paradigms play an important role in the management of group activities, such as reliable information diffusion in support of replication and cooperation. They consequently provide an appropriate framework for groupware applications support. To meet the new challenges posed by large scale distributed settings like the Internet, a new generation of group communication systems has emerged, built on the lessons learnt from early prototypes. This paper presents new services/features proposed by this new generation of systems and shows their relevance in the context of groupware support. Experiments with a cooperative application demonstrate how the features of a group-based system like NAVTECH can be used to enhance the functionality of groupware applications. NAVTECH is a modem group communication and activity support system developed at INESC.