It looks similar. MIT's Exokernel seems to use kernel-level hooks to control access to things like disk blocks and network packets. Arrakis takes a similar appr

It looks similar. MIT's Exokernel seems to use kernel-level hooks to control access to things like disk blocks and network packets. Arrakis takes a similar approach, but restricts those hooks to a subset that can be implemented in hardware instead of in the kernel.