[chasil]

True to form, Cutler had a break with DEC, and they gave him a carte-blanche VAX "skunkworks" with Prism/Mica.

DEC eventually shut this down, which prompted his departure for Microsoft. This is unfortunate for DEC, as they eventually poured the company into their Alpha RISC processor, which did not live as long as DEC hoped. Prism might have been a superior design.

At this time, Microsoft was maintaining a UNIX kernel in their Xenix product, so they knew a good kernel engineer when they met one. Microsoft was the leading UNIX vendor in the early 80's.

Cutler famously disparaged the UNIX kernel (his notable saying was "Get a byte, get a byte, get a byte byte byte" to the tune of the finale of Rossini's William Tell Overture).

Microsoft dumped their Xenix onto SCO about this time.

What is more interesting to me was Cutler's involvement with Azure. He must have had some sway over CBL-Mariner, Microsoft's RPM-based Linux distribution.

Much of Cutler's earlier work is documented in the "Showstoppers" book:

https://www.amazon.com/Show-Stopper-Breakneck-Generation-Mic...

The book doesn't really delve into the Xenix decisions, if I remember correctly.

Without Cutler, Microsoft would likely have ended up on a BSD kernel, as Apple did.

[voidfunc]

> What is more interesting to me was Cutler's involvement with Azure. He must have had some sway over CBL-Mariner, Microsoft's RPM-based Linux distribution.

He was involved with Red Dog (the modified Windows host that powers Azure).

He's not involved with CBL-Mariner team at all to my awareness. Mariner is mostly about solving a supply-chain problem at Microsoft... we have a ton of internal teams all using different flavors of Linux and packages have historically come from all over the place. With CBL-Mariner we are basically trying to unify on that and own the package build and distribution portion as well. There isn't much reason for a kernel designer to be involved in that as its a well-understood problem (and entirely different domain) and we already have internal upstream Linux kernel contributors (which is how produce -azure supported kernels).

[bluejekyll]

Apple didn’t end up on a BSD kernel. They started on Mach (from NeXT) and then made it more performant with XNU by not being so pedantic about microkernels.

BSD is just a supported kernel ABI.

Edit: I just found these docs, so I suppose it’s a bit more complicated that I’m stating, I.e. there are portions of the FreeBSD kernel directly in macOS https://developer.apple.com/library/archive/documentation/Da...

[chasil]

I only know what I've read.

"XNU was a hybrid kernel derived from version 2.5 of the Mach kernel developed at Carnegie Mellon University, which incorporated the bulk of the 4.3BSD kernel modified to run atop Mach primitives..."

https://en.m.wikipedia.org/wiki/XNU

[jbverschoor]

4.3BSD is not FreeBSD

[bluejekyll]

This is from the link I provided: “The BSD portion of the OS X kernel is derived primarily from FreeBSD, a version of 4.4BSD that offers advanced networking, performance, security, and compatibility features. BSD variants in general are derived (sometimes indirectly) from 4.4BSD-Lite Release 2 from the Computer Systems Research Group (CSRG) at the University of California at Berkeley.”

[fluidcruft]

After NeXTStep was adopted by Apple, they hired a bunch of the FreeBSD core developers and updated the BSD service and userland using FreeBSD. Apple was actually already messing around with Mach prior to that with MkLinux so there was some initial speculation that they might port to MkLinux rather than update NeXT's Mach+BSD hybrid.

[p_l]

The code updates are very limited, though. To the point that for one's own sanity it's better to assume userland is 4.3BSD unless marked otherwise (been burned by this myself in code that assumed every BSD had changes from ~1994 NetBSD)

[teh_klev]

I think you're replying to the wrong comment.

[p_l]

MacOS X essentially started by updating the NeXT core to latest OSFMK distribution, which was hybrid system (bsd server integrated into kernel space) powering the BSD alternative to SystemV - OSF/1 (most famous of them being DEC OSF/1 aka Digital Unix aka Compaq Tru64). They applied bits of FreeBSD to the bsd server code and over time improved its concurrency, but considerable portion of XNU is code that is called by bsd server but not part of bsd server (IOKit, among other things)

[formerly_proven]

> Cutler famously disparaged the UNIX kernel (his notable saying was "Get a byte, get a byte, get a byte byte byte" to the tune of the finale of Rossini's William Tell Overture).

I'm pretty sure that had to be in reference to STREAMS, because the original UNIX I/O model certainly is not byte-oriented. So basically, entirely irrelevant.

[chasil]

Maybe I should have used this one instead?

"Unix is a junk OS designed by a committee of PhDs." -Dave Cutler

[chasil]

...I just checked for Xenix in G. Pascal Zachary's "Showstopper! The Breakneck Race to Create Windows NT and the Next Generation at Microsoft."

Xenix is not in the index, which really detracts from the motivations behind the story.

[foobarian]

> Microsoft would likely have ended up on a BSD kernel

IIRC their TCP/IP stack was FreeBSD's at least for a while

[p_l]

Berkeley was paid to port TCP/IP to unix and as far as I know, part of the deal was that the code should be available to quickly port TCP/IP to more systems including non-BSD.

Thus considerable portion of Operating systems at one point or another used BSD4.3-derived network stack to detriment of network API evolution (sometimes updated with later code), some over time developing their own implementation.