I'd like mruby as some kind of fail-save boot system. Ruby powering the operating system as much as possible (ultimately ruby is just syntactic sugar over C, though, so I am fine using C of course).

The lack of documentation means that I'd just waste my time though. Not going to do that.

Also, I think mruby and MRI should not be separate. It doesn't do the project any good. It should be as modular as possible but one code base only.