Written in WebGL using three.js. Planet, nebulae, and stars are all generated procedurally using shaders. Textures are generated for a height map, moisture map, texture map, normal map, and roughness map. A biome lookup image is generated to control the distribution of colors. Unique names are generated and used as the random seed, which is then added to the URL string. If you find a cool planet, you can just share the link, and the planet you made will be shared.
Fly through a cityscape built entirely from algorithms. Each building is randomly generated by manipulating cube geometry. The position, size, and color of the buildings are generated from simplex noise maps. This was built for WebGL using the Three.js library.