> This leads me to wonder whether a user-mode GnuMach is > possible. The project home page talks about the benefits > of a user-mode kernel, and they all seem to apply, especially
Many of these are the same benefits of a microkernel design. That is to say, if what you really want is to debug anything other than the device drivers or the scheduler, then you can already do that conveniently on the Hurd because filesystems, network stacks, etc, are not in the kernel anyway. The stable way to do this, that is similar in concept to "user-mode linux" is to run a "sub-Hurd", which is what we call it when you start a second set of Hurd servers on top of the Mach microkernel after a first Hurd is already booted. The Hurd's `boot' program facilitates doing this. If you really want a user-mode Mach, then it certainly could be done. > the last one: > > "It doesn't need to be good for anything. It's fun!" We're way ahead of you here. The Hurd has always been on the cutting edge of not being good for anything.
