Surely a clean-sheet design started _now_ would be more interesting and perhaps even useful than a 21-year-old microkernel. Think about all the changes in architecture, networks, storage, etc.
We're in a world with consumer processors with 4-8 cores and hardware multithreading, GPUs that rival or exceed (in certain domains) the processing grunt of the CPUs, network cards that can talk to L2 cache, SSDs, etc.
Surely enough has changed that a clean-sheet design could be a lot more exciting - and even more practical - than trying to finish a design that hasn't succeeded for 2 decades. A clean-sheet design would at least be interesting - we already know you can build a workable system on top of a microkernel.
This isn't a claim to know what a clean sheet design would look like; I haven't really looked seriously at OS research in 15 years. I just strongly suspect you might do radically different, interesting designs in 2011 vs 1990.
At the end of the day it provides an OS to the FSF which they can control, and which isn't Linux. Even if it was in all ways equal to Linux in performance, and features (which seems doubtful) it's unlikely that it would deploy to any great extent.
Just like ReactOS is pretty much "pointless" (given that Windows costs basically nothing), Hurd is practically pointless because it competes with Linux purely on ideological grounds, and is arguably an inferior product. It simply doesn't have enough differentiating it at this point for anyone to really care.
On the other hand, maybe they'll finish it before I die, and maybe it'll contain some ground-breaking improvement, and we'll all be eating humble pie. Anything is possible. In the meantime if they want to carry on working on it, then good for them. Isn't that what open-source is all about?
Just curious, are there any such OS in development?
Anyway the Linux kernel is good enough, so the effort seems wasted.
My information only comes from my research made the better part of a decade ago(3) when they were seriously looking to port the microkernel to L4 from Mach 4(4), but sadly it appears that work was abandoned around 2006 [Dunno, why? It might be started again]. I suspect the low level switch had a lot to do with interest in a better kernel in OS X than what Darwin(5), XNU(6) on the Mac, could provide(7). In the Panther, pre-Leopard days there was a lot of interest in this(8) kind of project: large-scale microkernels(9).
I don't know if this effort will include the port from L4(10) with the Mach abstraction API to "save" the prior work in getting Mach to work with standard Debian without the extra header requirements.
Anyway, I'm going to get some coffee and lunch. If anyone wants to fund an idea like this, I would like to any of the number of amazing things that they are doing with non-tricyclic antidepressants these days. Just look at the good it did for Tony Soprano.
(1) http://www.debian.org/ports/hurd/hurd-install
(2) http://www.gnu.org/software/hurd/hurd/porting/guidelines.htm...
(3) http://www.shakthimaan.com/installs/debian-t41.html [Not me]
(4) http://www.gnu.org/software/hurd/microkernel/mach.html
(5) http://darwinbuild.macosforge.org/
(6) http://developer.apple.com/library/mac/#documentation/Darwin...
(7) I don't have any insider information. I'm just a developer.
(8) Mac OSX Panther for Unix Geeks, Brian Jepson, ISBN-13: 978-0596006075, Chapter 7
(9) http://www.ertos.nicta.com.au/software/darbat/
(10) http://kilobug.free.fr/hurd/pres-en/abstract/html/abstract.h...
