Source : Free On-Line Dictionary of Computing

Esterel
     
        A distributed language for synchronous interaction of
        {real-time} systems with their environment.  Uses explicit
        timing requests.  Esterel programs are compiled into finite
        {automata}.
     
        ["The ESTEREL Programming Language and its Mathematical
        Semantics", G. Berry & L. Cosserat, TR 327, INRIA, 1984].