A hardware description language (HDL) developed for very high speed integrated circuits. It is a language for describing digital electronic systems in an unambiguous way, and is designed to fill a number of needs in the design process. Firstly, it allows description of the structure of a system – how it is decomposed into subsystems and how those subsystems are interconnected. Secondly, it allows the specification of the function of a system using familiar programming language forms. Thirdly, as a result, it allows the design of a system to be simulated before being manufactured, so that designers can quickly compare alternatives and test for correctness without the delay and expense of hardware prototyping. Fourthly, it allows the detailed structure of a design to be synthesized from a more abstract specification, allowing designers to concentrate on more strategic design decisions and reducing time to market.