LARA

The OCaml programming language: http://caml.inria.fr/ is convenient for writing implementations for this class because of its support for algebraic data types and pattern matching, which makes dealing with abstract syntax trees easier.

http://www.csc.villanova.edu/~dmatusze/resources/ocaml/ocaml.html is a good crash-course in basic of OCaml. At the bottom of the file you are going to find pointers to the official OCaml manual and also to an introductory course given at UPenn.