Scheme

Scheme is a functional programming language. Its goal is to offer a mathematically sound language based on lambda calculus (with eager evaluation).

It adheres to minimalist design philosophy, defining a tiny standard core with robust language extension features. Its elegance and compactness have made it popular among educators, language designers, programmers, implementors, and hobbyists.

The Scheme programming language is a member of the Lisp family. Scheme is referred to as a lisp-1 because it employs a single namespace to name functions and other variables.

Aims to standardize Scheme have been attempted throughout the years, including the R5RS standard, the somewhat contentious R6RS standard, and the most current standard R7RS, which attempts to break the language into small and big (ongoing) standards.