High Quality Content by WIKIPEDIA articles! FAUST (Functional AUdio STream) is a programming language that provides a purely functional approach to signal processing while offering a high level of performance. FAUST aims at being complementary to existing audio languages by offering a viable and efficient alternative to C/C++ to develop signal processing libraries, audio plug-ins or standalone applications. The language is based on a simple and well defined formal semantics. A FAUST program denotes a signal processor, a mathematical function that transforms input signals into output signals.