Matthias Buelow  <mkb@mukappabeta.de> wrote:
+---------------
| William Bland wrote:
| > everything else back to it, so I was wondering:  does a microkernel
| > approach make sense at all in a Lisp-based operating system?
| 
| the question might also be whether a microkernel-based system makes any 
| sense at all in a commercial environment.  all the big vendors have 
| either abstained from, or moved from implementing microkernel general 
| purpose OSes.
+---------------

What?!? You don't include IBM as a "big vendor"?!?  Or maybe you just
have never thought about VM/370 -> VM/390 -> z/VM as a "microkernel",
but it really is (even though IBM calls it a "hypervisor"), so much
so that whole operating systems run on top of it!  ;-}

Note: I recently took a look as "Linux for zSeries", and was quite
surprised at what they've managed to accomplish: imagine running
MVS, CICS, TSO, CMS, and several hundred Linux system images on
the same piece of hardware all at the same time!

In fact, it got me starting about who might fund a port of CMUCL
(and/or SBCL) to zSeries [since zSeries is 64-bit capable, and
64-bit SuSE already runs on it]...

+---------------
| a microkernel is nice for experimenting and research.  for a real-life 
| implementation with a rather fixed, well-known feature set, it doesn't 
| make much sense.
+---------------

The long & continuous history of IBM microkernel (hypervisor) operating
systems from CP-67 -> VM/370 -> VM/390 -> z/VM disputes that.


-Rob

-----
Rob Warnock			<rpw3@rpw3.org>
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