Two things come to mind, from less-far-out to further-out: - A capability-based operating system, see: http://en.wikipedia.org/wiki/Capability-based_addressing

Two things come to mind, from less-far-out to further-out: - A capability-based operating system, see: http://en.wikipedia.org/wiki/Capability-based_addressing http://en.wikipedia.org/wiki/Capability-based_addressing - Anything microkernel-based (Minix!) For pete's sake guys, why don't we have this already in our mainstream OSes? I'd happily take a performance hit of 10% in return for the enormous benefits (stability, security, design elegance). Personally I don't think compile-time guarantees are a good idea, because the resulting system strikes me as very vulnerable to that one thing the developers overlooked.