tl;dr: A beginner-friendly introduction to Racket, a modern descendant of Lisp/Scheme, covering its history from McCarthy's 1958 Lisp through Scheme to today's "language-oriented programming" philosophy. The tutorial walks through installation via DrRacket, basic syntax (everything is `(operator args...)`), functions, lists, higher-order functions like map/filter/foldl, and recursion with a Sierpinski triangle example. It culminates in demonstrating homoiconicity and macros by implementing a `while` loop from scratch, showing how Lisp lets you extend the language itself.