It's nape-js https://newkrok.github.io/nape-js/index.html https://newkrok.github.io/nape-js/index.html While the gummy geometry one is a little twitchy, but m

It's nape-js https://newkrok.github.io/nape-js/index.html https://newkrok.github.io/nape-js/index.html While the gummy geometry one is a little twitchy, but most all the other demos were very stable, much more than most other 2d solvers I've seen.