My esolangs:

1. Minus (2007) - A very simple imperative language with only one instruction, yet decently expressive with a 227 character self interpreter.
2. Golfscript (2007) - Arguably the first ever golf language, not without its flaws but surprisingly powerful for how simple it is.
3. Universal Lambda (2008) - Implementation of John Tromp's binary lambda calculus using bytes with church encoding for IO.
4. Nibbles (2021) - My attempt to bring simplicity back to golf languages, about 3x smaller on average than golfscript. Functional programming in half byte instructions.