The effect is based on video feedback implemented with WebGL and its shading language, which means most of the work is done on your GPU. The videos are in WebM format which works on Chrome and Firefox.
Besides the presets, click to open the controls then paste in the URL of any video from YouTube to change the source. Then adjust the parameters to get it looking good. Then click on "share" and send the URL anywhere to reproduce what you see.
Basically it combines luma key with a feedback layer transformed with scale-rotate-translate and mirror tiling. The scale and rotation are connected to the mouse, but if you don't move the mouse for a while, then they get adjusted automatically.
You can get the source code from Google Code.