OT - both Safari (w/o Flash) and Google Chrome max out all CPU cores as long as this site is open. The visualisation might need an upper limit on the work it is doing per second...
I developed this on Chrome on a Mac and Chromium on Ubuntu, and it worked on both of those. Sorry it's giving you problems.
I would've hazarded a guess at a Webkit bug, but OP mentioned she developed this on Chrome..