If you find this interesting you may want to read about this more current research: http://www.openmirage.org/ http://www.openmirage.org/ To quote from the vis

If you find this interesting you may want to read about this more current research: http://www.openmirage.org/ http://www.openmirage.org/ To quote from the vision paper http://anil.recoil.org/papers/2010-bcs-visions.pdf http://anil.recoil.org/papers/2010-bcs-visions.pdf Mirage is written in the spirit of vertical operating systems such as Nemesis [17] or Exokernel [10], but differs in certain aspects: (i) apart from a small runtime, the operating system and support code (e.g., threading) is entirely written in OCaml; and (ii) is statically specialised at compile-time by assembling only required components (e.g., a read-only file system which fits into memory will be directly linked in as an immutable data structure). These features mean that it provides a stronger basis for the practical application of formal methods such as model checking; and the removal of redundant safety system checks greatly improves the energy efficiency of the system.