Check this out: https://effacestudios.github.io/PlanetGenerator/
It's the same thing but with the ability to download the Planet as PNG (but not the Rectangular surface of the map)
Indeed, the author sent me the code and now it's also up here. :)
Oh, and I have a test version that produces the rectangular map too, but the map looks awful. You can really tell it's perlin noise in a way that's hidden by when it's a rotating sphere.
@Zarkonnen I think it would still be worth releasing. For my purposes / game project, a rectangular map is more important for its shape and information rather than its looks.
Please release it anyway!