Very impressive, especially the adaptive topology feature, I don't believe even Mudbox has that.

Adding some sort of collaborative features would would be plausible and really cool (keep perspective and settings local, sync model updates).

Is this open source? I would love to poke around adding some real time collab features.

Github link: https://github.com/stephomi/sculptgl. License is MIT. This is from the main page (http://stephaneginier.com/).