Scheme (programming Language) - Implementations

Implementations

The elegant, minimalist design has made Scheme a popular target for language designers, hobbyists, and educators, and because of the small size of a typical interpreter it is also a popular choice for embedded systems and scripting. This has resulted in scores of implementations, most of which differ from each other so much that porting programs from one implementation to another is quite difficult; and the small size of the standard language means that writing a useful program of any great complexity in standard, portable Scheme is almost impossible. The R6RS standard specifies a much broader language, in an attempt to broaden its appeal to programmers.

Almost all implementations provide a traditional Lisp-style read–eval–print loop for development and debugging. Many also compile Scheme programs to executable binary. Support for embedding Scheme code in programs written in other languages is also common, as the relative simplicity of Scheme implementations makes Scheme a popular choice for adding scripting capabilities to larger systems developed in languages such as C. Gambit, Chicken and Bigloo work by compiling Scheme to C, which makes embedding particularly easy. In addition, Bigloo's compiler can be configured to generate JVM bytecode, and it also features an experimental bytecode generator for .Net.

Some implementations support additional features. For example, Kawa and JScheme provide integration with Java classes, and the Scheme to C compilers often make it easy to use external libraries written in C, up to allowing the embedding of actual C code in the Scheme source. Another example is Pvts, which offers a set of visual tools for supporting the learning of Scheme.