Not that this was your point, really, but I couldn't find any restriction
  on commercial distribution except Section 4, which mostly talks about
  indemnification.  What am I missing?  

Which raises another issue - indemnification probably ought not to be
considered a reasonable license term.  But in this particular case,
that only applies if there is commercial distribution of openmotif,
and then only for acts of the commercial distributor.

If someone creates a derived work from NetBSD, and distributes it
other than as an open source program (which is allowed), then one
can't use openmotif on that derived work.

The question this raises is whether the ACCEPTABLE_LICENSES variable
is about use of a pkgsrc-ized program, or inclusion in arbitrary
derived systems.  I think it means the former.

All that said, if someone can make a case that the openmotif license
is not either Free(rms) or Open Source, I'd be happy to have it
require an ACCEPTABLE_LICENSES entry.  Being careful about licenses is
one of NetBSD's strengths, and that only happens by care at the edge
cases like this.

-- 
        Greg Troxel <gdt@ir.bbn.com>