Making free sky

This is a complete Blender Cycles procedural sky generator.

Story

By the end of 2015 I needed a sky environment for some animations. After spending a lot of time in searching for free HDR images, I came to the realization that HDR images don’t give much flexibility, for example they cannot be animated and are low resolution, so I started making something that Blender needed for years: a sky generator full of clouds that is very quick to render.
After trying a lot with world node setups, I realized that the rendering time was too slow because of the too many used nodes.
So 3 months ago I started this project and today I’m proud to present it to everyone!