Synchronous languages for hardware and software reactive systems

Synchronous languages are dedicated to hardware, software, or mixed reactive systems that maintain a continuous interaction with their environment. They come in two classes: data-oriented languages such as Lustre and Signal, which are targeted to data-intensive applications such as continuous control or signal processing, and control-oriented languages or visual formalisms such as Esterel, Statecharts, or Argos, which are tailored for discrete controllers. Data-oriented languages are equational and involve combinational or delayed operations over multiply-clocked signals. Control-oriented languages have explicit primitives for sequencing, concurrency, and process preemption.