Racket (programming language)

The best choice if you want to understand functional programming from first principles. Racket comes with DrRacket, a beginner-friendly editor, and pairs with How to Design Programs, a free online textbook by Racket's own designers that teaches recursion, higher-order functions and program design with unusual care. It is also the place to try building your own small languages with macros, which changes how you see every other language. Racket 9.0, released in November 2025, added parallel threads to a runtime that already had green threads. Do not expect a big jobs market or a deep pool of production libraries: this is the language that makes you a better programmer in others.