I have a hand-written BF interpreter in WAT, along with hand-written asm.js for comparison, over here https://github.com/magcius/bfasm https://github.com/magciu

I have a hand-written BF interpreter in WAT, along with hand-written asm.js for comparison, over here https://github.com/magcius/bfasm https://github.com/magcius/bfasm