I've seen a website background that looked like the shifting gif. Something fancy in js that some developer made. Looked really neat. Ate 100% of my CPU to look

I've seen a website background that looked like the shifting gif. Something fancy in js that some developer made. Looked really neat. Ate 100% of my CPU to look at their main site or blog, but it did look neat. Nice to get an idea of what they were doing.