Team automata have been proposed as a formal framework for modelling both the conceptual and the architectural level of groupware systems. They are defined in terms of component automata (labelled transition systems) together with an interconnection mechanism which is based on shared actions (synchronizations). Components can be combined in different fashions depending on which actions are to be shared, and when. This set-up makes it possible to distinguish between different types of synchronizations and allows to represent hierarchical systems. A survey is presented including a brief comparison with some related models.