An extensive, clear explanation of how to write a lambda calculus interpreter in Haskell.
A narrative scripting engine similar to Ink (http://github.com/inkle/ink), but more portable and implemented using Haxe.
Brian gives a deep explanation of how Monte Carlo Tree Search (a key technique for game AIs) works. He implemented the AlphaGo paper from scratch, so he should know!
A CHIP-8 (https://en.wikipedia.org/wiki/Chip-8) interpreter written in Rust.
A tool for turning text into braille dotgrids.
An implementation of Lamba calculus using Elixir.
A Harry Potter-themed "shell for wizards"!
A compiler for a simple language using LLVM.
A programming language aiming for control and simplicity, similar to C but with fewer sharp edges.
A "stochastic markup language" that lets you easily write chance-determined text.