This paper provides an overview of the STATEMATE system, constructed over the past several years by the authors and their colleagues at Ad Cad Ltd., the R&D subsidiary of i-Logix, Inc. STATEMATE is a set of tools, with a heavy graphical orientation, in- tended for the specification, analysis, design, and documentation of large and complex reactive systems, such as real-time embedded sys- tems, control and communication systems, and interactive software or hardware. It enables a user to prepare, analyze, and debug diagram- matic, yet precise, descriptions of the system under development from three interrelated points of view, capturing structure, functionality, and behavior. These views are represented by three graphical languages, the most intricate of which is the language of statecharts [4], used to depict reactive behavior over time. In addition to the use of statecharts, the main novelty of STATEMATE is in the fact that it "understands " the entire descriptions perfectly, to the point of being able to analyze them for crucial dynamic properties, to carry out rigorous ex- ecutions and simulations of the described system, and to create run- ning code automatically. These features are invaluable when it comes to the quality and reliability of the final outcome.

Visual programming arguably provides greater benefit in explicit parallel programming, particularly coarse grain MIMD programming, than in sequential programming. Explicitly parallel programs are multi-dimensional objects; the natural representations of a parallel program are annotated directed graphs: data flow graphs, control flow graphs, etc. where the nodes of the graphs are sequential computations. The execution of parallel programs is a directed graph of instances of sequential computations. A visually based (directed graph) representation of parallel programs is thus more natural than a pure text string language where multi-dimensional structures must be implicitly defined. The naturalness of the annotated directed graph representation of parallel programs enables methods for programming and debugging which are qualitatively different and arguably superior to the conventional practice based on pure text string languages. Annotation of the graphs is a critical element of a practi...