After a lot of random poking about, I finally found it! https://github.com/espruino/Espruino/tree/master/libs/js/banglejs
@andrewg_oz started
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
After a lot of random poking about, I finally found it! https://github.com/espruino/Espruino/tree/master/libs/js/banglejs