> There are no really relevant, characteristic parts of Mach incorporated into  
> the way NetBSD does business.

This is just plain wrong.  The whole VM system was adapted from Mach, 
as explained in the 4.4BSD book (McKusick et al).  Try grep'ing for 
'Mach Operating System' in vm/*.[ch].  Managing virtual memory is 
a fundamental aspect of "the way NetBSD does business" in my view.

The current NetBSD kernel debugger, ddb, was also lifted from Mach. 


                            -Jay