Racket is a general purpose programming language derived from Lisp. It is called a "programmable programming language" because its built-in macro system allows a programmer to redefine everything about the language itself. For this reason, Racket is often used to design and implement custom programming languages for specific project needs.
Racket was originally developed as part of the PLT ("programming language team") project by computer scientist Matthias Felleisen in 1995. His intention was to create a language which would help novice programmers learn more about the potential of computers.
Hello, World! written in Racket
(printf "Hello, World!")