Computer art, JavaScript audio, graphics and UI stuff. Also ravings about AI, the Singularity, Robotic Ethics
One of the best, most thought-provoking websites I’ve seen Brett Victor
And this guy is an amazing CSS/JavaScript/Web “Artist” who shares his knowledge generously Hakim
Mozillas Developer Network Shared knowledge for the Open Web
Here’s a neat Canvas scratchpad! Canvas Scratchpad
And a very neat Web Audio Playground!