Pachuco is a recreational project I've been working on for a while. It's a self-hosting compiler for a dialect of the Lisp programming language (and it also has a lot in common with Scheme). It generates i386 or x86-64 assembly code directly, rather than compiling to another high-level language or virtual machine. The system is about 5000 lines of code, including the compiler, runtime, garbage collector, and interpreter (used in the macro system). The whole system is written in the Pachuco language, except for a minimal amount of C and Common Lisp code to allow the system to be bootstrapped.