#lang racket
(provide hello)
(define (hello [name "World"])
(string-append "Hello, " name "!"))"Racket (formerly named PLT Scheme) 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." - Wikipedia
You can learn the basics of Racket through a coule of books. Start by checking out How to Design Programs or the slightly less formal but enjoyable Realm of Racket.
The official language website can be found at http://racket-lang.org/ and the source code is at https://github.com/racket/racket/. You can find the community on twitter, email or slack.
Join the Racket track
Exercism is fantastic in learning new languages but that is not the extent of it. If you are a "more experienced" programmer you may have encountered impostor syndrome: the idea you don't really know what you think you know. Exercism lets you solve problems and put them in the space of open feedback which is a tremendous learning opportunity to explore the depth of your own knowledge. Even if you have been programming in a language for awhile it is worth checking into Exercism to see where you stand with current implementation practices.
Once you join the Racket language track, you will receive support and feedback from our team of mentors. Here are the bios of a few of the mentors of this track.
These are a few of the 31 exercises on the Racket track. You can see all the exercises here.