Title edited for length from "Coding Agents Build Chess Engines From Scratch in Rust, C++, COBOL, Rocq, LaTeX, Brainfuck, and More"

He also has dedicated entries on two very special case, the engine running within pdflatex https://blog.mathieuacher.com/TeXCCChessEngine/ and the one in Brainfuck https://blog.mathieuacher.com/BFChessChessEngineBrainfuck/ which are seemingly the first of their kind.