You should check out libfive! https://libfive.com/studio/. Previously discussed here: https://news.ycombinator.com/item?id=26930822. It is the child of Ao, previously discussed here: https://news.ycombinator.com/item?id=12319406.
libfive is only concerned with geometry, though, so you can't do any of the coloring/shading/procedural graphics stuff. And no animations. I think of Bauble as closer to Shadertoy than libfive in purpose, although they appear very similar.