I didn't have this idea exactly but I did play around with sqlite as an embedded database for packing ruby apps into a single file a while ago. It was less direct than this: you basically compiled all the dependencies (including .so's) into a fake filesystem that an overridden `require` loaded from, which was unpacked to a `:memory:` database at runtime from a `.data` section that got bolted onto the interpreter. It died when 1.8->1 9 changed how the build system works and I never got round to updating.

A version based on this which carries around an overlay filesystem would be comparatively straightforward, the hard work is already done.