Open to questions and all that- you can download the source just by, well, viewing it, it's not obfuscated, and it's totally free to use. If you use it and want to credit, the name's Laurence Smith - and if you do, please link me so I can have a peek at what you've used it on.
Well, anyway; this thing relies on CSS3 transitions with a 3 second linear transition time. JS changes the opacity of every block within a random range every 0.5 seconds, but since it takes ages to transition, it's quite a soft effect.
Well, anyway; this thing relies on CSS3 transitions with a 3 second linear transition time. JS changes the opacity of every block within a random range every 0.5 seconds, but since it takes ages to transition, it's quite a soft effect.