Racket is an extensible general programming language in the Lisp family.
Racket is a general purpose, multi-paradigm programming language in the Lisp/Scheme family. One of its design goals is to serve as a platform for language creation, design, and implementation. The language is used in a variety of contexts such as scripting, general-purpose programming, computer science education, and research.
Home page: http://www.racket-lang.org