Will recommending my own project get me hell-voted? Cixl is a straight forward 3-stage (parse/compile/eval) interpreter that is designed to be as fast as possible without compromising on simplicity, transparency and flexibility. The codebase has no external dependencies and is currently hovering around 7 kloc including tests and standard library. There are some articles explaining design decisions, but I've been mostly busy with code. The code should be perfectly readable though, and contains plenty of good ideas distilled from 32 years of daily practice.