I'm not well-versed enough into "modern" web stack to troubleshoot, but there is something wrong with the scrolling on their website. Doesn't inspire much confidence into web audio. I'm not entirely sure why browser would be a good fit for an audio synth plateform, to say the least.

Faust is nice tho, a combinator language with stream processor semantics. There are lots of things to improve (quality of life things for organizing code, more typing, better semantics for the surface language which currently is ugly macro expansion where it could've been a simple lisp or even better a mini-ML), but it's also currently one of the best thing in town for functional synthesis.