Date Added: Nov 2009
In computer science, there is a distinction between closed systems, whose behavior is totally determined in advance, and open systems, that are systems maintaining a constant interaction with an unspecified environment. Closed systems are naturally modeled by transitions systems. Open systems have been modeled in various ways, including process algebras, I/O automata, "Modules", and interfaces. Games provide a uniform setting in which all these models can be cast and compared. In this extended paper, the authors discuss the features and costs related to the game-based approach to open systems, referring to some of the existing models. Finally, they describe a new model of interface, called sociable interface, which is geared towards easier specification, improved reusability of models, and efficient symbolic implementation.