In this talk, you'll learn how I built DIVSPL (Dustin Ingram's Very Special Programming Language), a tongue-in-cheek domain-specific language, which is particularly good for implementing FizzBuzz -- as quickly as possible. We'll build DIVSPL with RPLY, an implementation of David Beazley's PLY (but with a "cooler" API) and make it compatible with RPython, a restricted subset of the Python programming language. Along the way, you'll learn about lexers, parsers, and grammars, and in the end, you'll know how to build your own language.