[spijdar]

OpenStep was still based on Mach 2 and (encumbered) 4.3BSD.

OS X Server 1.0 was very OpenStep like yes, it used the old Display Postscript server and was more compatible with next/openstep (I think the display servers were similar enough you could forward OpenSTEP software to a OS X Server 1.0 windowserver), but I believe it was based on the un-encumbered XNU, and couldn't directly run OpenSTEP programs due to this impedance. I'm fairly certain Rhapsody is the same, using the OSFMK kernel and 4.4BSD "lite".

At least, I don't think OS X Server 1.0 software would have worked on the OpenSTEP for Enterprise stuff?

[lukeh]

Rhapsody was still pre-Mk but had 4.4BSD userland. It could run OPENSTEP binaries if you copied the shared libraries over, from memory one of the ex-NeXT engineers did this for fun.

[spijdar]

Cool :) this is all before my time but I've got a few Sun boxes running various old BSDs and Nextstep 3.3.

I've always been kind of curious how hard it'd be to get NetBSD's COMPAT_DARWIN and COMPAT_MACH to run the next/openstep userland...

[pjmlp]

That much I don't recall, maybe, not sure.