The Firefox on my work desktop (7, Linux) slows to a crawl on that site, I suspect it's because of the doodle effect. Annoying gimmick, sorry.

Firefox canvas performance is a joke. You should upgrade to Chrome.

Firefox (10, linux) performance is fine for me; it may be his browser version or something else.

Works fine on my own machine (13, Linux). But that doesn't help people who are stuck on machines where it doesn't. I suppose the code could detect low frame rates and reduce quality or shut down?

Harmony.js: There you go > http://mrdoob.com/projects/harmony/

Although, I don't find harmony.js a very nice way sorts.