Chicken (Scheme implementation)

Chicken (stylized as CHICKEN) is a programming language, specifically a compiler and interpreter which implement a dialect of the programming language Scheme, and which compiles Scheme source code to standard C. It is mostly R5RS compliant and offers many extensions to the standard. The newer R7RS standard is supported through an extension library. Chicken is free and open-source software available under a BSD license. It is implemented mostly in Scheme, with some parts in C for performance or to make embedding into C programs easier. Chicken's focus is quickly clear from its slogan: "A practical and portable Scheme system". Chicken's main focus is the practical application of Scheme for writing real-world software. Scheme is well known for its use in computer science curricula and programming language experimentation, but it has seen little use in business and industry. Chicken's community has produced a large set of libraries to perform a variety of tasks. The Chicken wiki (the software running it is also a Chicken program) also contains a list of software that has been written in Chicken. Chicken's other goal is to be portable. By compiling to an intermediate representation, in this case portable C (as do Gambit and Bigloo), programs written in Chicken can be compiled for common popular operating systems such as Linux, macOS, other Unix-like systems, Windows, Haiku, and mobile platforms iOS and Android. It also has built-in support for cross-compiling programs and extensions, which allows it to be used on various embedded system platforms. Like many Scheme compilers, Chicken uses standard C as an intermediate representation. A Scheme program is translated into C by the Chicken compiler, and then a C compiler translates the C program into machine code for the target computer architecture, producing an executable program. The universal availability of C makes it useful for this purpose. Chicken's design was inspired by a 1994 paper by Henry Baker that outlined an innovative strategy to compile Scheme into C.