...I have thought about it a fair amount. As it's a pretty personal project, I'm the only one working on it, and I'd prefer to keep the development closed for now. I'll probably change that at some point, especially once it is in a more complete state.
Ah, I see - I get that. IMO it might be better since your engine would get popularity and that would introduce contributions from other people, which is a win-win. P.S. it being public domain is very cool of you OP.