This started as me following along with Ruslan Spivak's Interpreter series (http://ruslanspivak.com/lsbasi-part1/), implemented in C.
After reaching part 7 of the series, this interpreter has evolved on its own, ahead of the blog posts.
The interpreter will eventually be an implementation of Rust.