This library transpiles JS to WebGL which allows computations to run in parallel on the GPU instead of one by one on the main JS thread.
I used this library to prototype shademap but I think it's no longer maintained. I PRed a fix to correct atan2 over a year ago and no movement [1].
Because this library optimized for simplicity over performance, switching to vanilla WebGL will get you better performance (especially with textures) in the long run.
I do highly recommend it if you're a web developer interested in harnessing parallel processing.