Guix

TinyScheme is a light-weight Scheme interpreter that implements as large a subset of R5RS as was possible without getting very large and complicated.

It's meant to be used as an embedded scripting interpreter for other programs. As such, it does not offer an Integrated Development Environment (IDE) or extensive toolkits, although it does sport a small (and optional) top-level loop.

As an embedded interpreter, it allows multiple interpreter states to coexist in the same program, without any interference between them. Foreign functions in C can be added and values can be defined in the Scheme environment. Being quite a small program, it is easy to comprehend, get to grips with, and use.