They can all be done in JS (modified to remove threading, of course). In fact, many of them already run in emscripten/pepper.js (see http://trypepperjs.appspot.com).
Which is a pretty big deal imo considering Voroni goes from 3.3 fps with 1 thread to 12 fps with 8 threads on my laptop with an intel quad core with hyperthreading.
js has plenty of 2d physics sims but i have yet to see a decent 3d one like this.