extensible programming language in the Scheme family
Racket (previously PLT Scheme) is a programming language suitable for scripting and application development, including GUIs and web services.
It supports the creation of new programming languages through a rich, expressive syntax system. Supplied languages include Typed Racket, ACL2, FrTime, and Lazy Racket, and R6RS Scheme.
Racket includes the DrRacket programming environment, a virtual machine with a just-in-time compiler, tools for creating stand-alone executables, the Racket web server, extensive libraries, and documentation for both beginners and experts.