Sydde
macrumors 68030
You are referring to the GNU user space here right? The GNU OS with it's own kernel, is GNU hurd, ie the Mach kernel with GNU user space. No Linux.
I have heard (no pun intended) of something like Debian running in L4 Userland, though that seems kind of silly, since the Linux kernel is unified. The point of using a microkernel is to break up the system into independent modules/daemons that can be managed more easily. Hurd on Mach does run, but, after nearly 30 years of development, it is still not a candidate for a viable OS. I think this is partly due to Mach cruft, but they have not come up with a better kernel to build it on. Seems to me they were talking about ultimately making Hurd kernel-agnostic, but one thing they do a lot of over there is talk about stuff.