To a language designer, Racket is a programming language laboratory. That is, Racket comes with a unique collection of linguistic mechanisms that enable the quick construction of reliable languages, language fragments, and their composition. These tools are so easy to use that plain programmers can design a language after a little bit of instruction. So when a well-trained programmer decides that none of the available dialects is well-suited for a task, he designs a new dialect and writes his program in it. As Paul Hudak said, “the ultimate abstraction is a domain specific language.” — Racket is…