Anyway, moscow is the project I've been fiddling with for most of that time, but I've recently decided to take a new direction with it, something a little unusual: the plan is to make it run provably typesafe and memory-safe "user mode" code in the kernel address space. My estimates are that I can get IPC setup time down to approx 20 CPU cycles and 2 memory accesses, which should make a very high performance microkernel viable. Target platform is x86-64; tools are g++/nasm (for kernel code) and llvm-g++ (for user code, inc. drivers).