Yes. it's processing.js running inside the Flash Player, which then ignores the heavily optimized cross-platform rendering power of Flash, and instead proxies its drawing requests to a <canvas> element. I don't care, I like it.
It works in Firefox 2. Something doesn't quite work on Safari, although there's no fundamental reason why it couldn't be made to work (beside the lack of a point, of course.)
If you use Firebug and get some strange errors on this page, it's time to upgrade Firebug.
You'll like the new version better, I promise.
If you're not using Firebug, you're missing out. Install it.
Here are a few samples processing thingies ripped from John's list. The second sample reacts to mouse motion. Feel free to try running more examples, but be warned that you might need to debug things here and there.