I wasn't but I'll have to read more! Some good relevant discussion here too https://news.ycombinator.com/item?id=7554921 . I wanted to keep this project in user-space, but there's a lot of interesting ground on the OS side of things too. Something like Theseus <https://github.com/theseus-os/Theseus> is also interesting, providing similar protections (in theory) by enforced compiler invariants rather than hardware features.