It's based on infrared and visible light data from EUMETSAT, processed to enhance the clouds and try to reduce the impact of surface temperatures on the final image.

I built it because it's surprisingly hard to find these kinds of images in a format that's useful to developers and hobbyists. I was building a 3D ISS tracker and wanted to include live clouds but couldn't find anything good, so I got sidetracked, and here we are.