Real-time browser based path tracer

While searching the net for ways to improve convergence in dynamic, path traced environments, I stumbled upon this neat web-based path tracer created by Edward Porten:

http://www.openprocessing.org/visuals/?visualID=14228

It uses progressive spatial caching and runs pretty fast despite being CPU-based.

Also check out some other browser-based demos from the same author at http://www.openprocessing.org/portal/?userID=6535

The Sphere flake tracer uses a cool looking frameless rendering technique, roughly comparable to frame averaging.

"Hair Ball" and  "Terrain Ray Marching"  are awesome as well.