The Ptolemy II framework for visual languages

This paper presents the Ptolemy II framework that supports the visual modeling and design of heterogeneous systems. Models in this framework are structured as hierarchical clustered graphs. The framework provides the infrastructure to support the implementation of a variety of models of computation as domains. Heterogeneous systems are modeled by hierarchically combining different domains. We describe the implementation of the *charts formalism (a generalization of Statecharts) in Ptolemy II as an illustration of the flexibility of this approach.