This is a port of Řrřola's amazing 256-byte intro Puls to WebGL. The effect is implemented as a single GLSL fragment shader, and thus runs pretty much entirely on the GPU. It was written while trying to learn more about WebGL, and also to gain better understanding of Řrřola amazing little piece of code.
It is not an entirely accurate translation of the algorithm, but it is fairly close. It is also nowhere near 256 bytes - it is closer to 4k, not counting the parts that aren't related to the effect as such.
It currently only works in the latest WebKit version with 3D canvas turned on (the nightly builds currently do not have it turned on) or Firefox. Firefox seems to have some bugs related to sizing the canvas, at least on OS X.