MIT license. https://github.com/DRincs-Productions/NQTR-System?tab=MIT-1-ov-file#readme
I'm also working on moving this library to my game engine Pixi'VN (https://drincs-productions.itch.io/pixi-vn). I'm telling you this because I don't like the end much. So if you haven't started the software development yet you might be interested in pixi-vn