People sometimes ask on HN about good books on implementing programming languages. One of the best textbooks I know on type theory is also a pretty good book f

People sometimes ask on HN about good books on implementing programming languages. One of the best textbooks I know on type theory is also a pretty good book for getting a programming language up and running: Types and Programming Languages by Ben Pierce. https://mitpress.mit.edu/books/types-and-programming-languages https://mitpress.mit.edu/books/types-and-programming-languag... The book starts off implementing the untyped lambda calculus and then adds more and more interesting kinds of types. There's a tarball somewhere on the course website that has all the code from the book, and it's kind of fun to play with all the systems it covers.