You're getting downvoted to hell for a small misunderstanding, and the replies aren't necessarily helping.

NeXT is the reason Apple went with a UNIX-type OS that evolved into OS X, yes.

Linux is also a UNIX-type OS, but is not an ancestor of OS X.

Linux is so popular now that it's easy to identify it with UNIX but historically it's only one of several implementations that work in roughly similar ways.

Other replies are telling you which code OS X was actually descended from.

Linux = "Linux Is Not UniX"

It's in the name.

I never heard that one before. I thought Linux was just a conflation of "Linus" and "Unix", while GNU was a recursive abbreviation of "GNU is Not Unix".

Linux means "Linus's Unix" and the name came from the sysadmin at funet.fi who had to give the kernel a home subdirectory when Linus asked him to host the kernel on an FTP site ..

I think you're confusing Linux with GNU.

(I'd just like to interject, etc.)

As far as I know, Apple has never used Linux for anything in any capacity. OSX's kernel is XNU, and it's a hybrid of BSD code and Mach.

Not never, but it is close. https://en.wikipedia.org/wiki/MkLinux:

”MkLinux started as a project sponsored by Apple Computer and OSF Research Institute, to get "Linux on Mach" ported to the Macintosh computer and for Apple to explore alternative kernel technologies on the Mac platform. At the time, there was no officially sponsored PowerPC port of Linux, and none specifically for Macintosh hardware”

I actually ran this OS for a little while. I wonder if I still have the CDROMs...

Apparently a Linux-based system was a contender for iPhone OS:

> Around 2005, Jobs faced a crucial decision. Should he give the task of developing the device’s software to the team that built the iPod, which wanted to build a Linux-based system? Or should he entrust the project to the engineers who had revitalized the software foundation of the Macintosh? In other words, should he shrink the Mac, which would be an epic feat of engineering, or enlarge the iPod? [1]

When this article first came out, I made the assumption that this statement meant iPod OS was Linux-based---also feel like I heard that somewhere else---but I have not found any sources to confirm this. Anyone else know?

[1]: https://www.bloomberg.com/news/articles/2011-10-12/scott-for...

The iPod ran a custom firmware developed by Pixo. Not, AFAIK, Linux based. There was however a homebrew project to run Linux on some iPods.

http://www.sfgate.com/default/article/Little-known-startup-w...

https://en.wikipedia.org/wiki/IPodLinux

How about mkLinux? https://news.ycombinator.com/item?id=10764605

Maybe not in anything they've shipped as a consumer product, but what's powering their services?

So OSX has nothing to do with unix/linux?

macOS (and older OSX releases) are UNIX (see http://www.opengroup.org/openbrand/register/brand3627.htm for certifications). Linux is not UNIX (its not certified - not many are - see http://www.opengroup.org/openbrand/register/index.html) and could best be described as POSIX like.

Thanks for the explanation. I thought Unix and Linux had something to do with eachother, but looking at the downvotes, I was wrong :D

Richard Stallman announced that he was working on a Unix clone on September 27, 1983. [1] This was the GNU Project from GNU's Not Unix.

Stallman was a prodigious programmer and wrote GCC (GNU C), a debugger and Emacs. He also created the GPL and founded the Free Software Foundation (from which the "open source" movement split off).

GNU was most of an OS by 1990 but didn't have a proper kernel (which was intended to be the ambitious Hurd).

In an unrelated move, Linus Torvalds used Stallman's tools to write a mini-OS and released it under Stallman's license in 1991. It naturally got incorporated into what some people (including Stallman) then called GNU/Linux. It was, in code terms, roughly 97% GNU and 3% Linux.

The naming is arguable because Linux was never a GNU or FSF development. However, Stallman's GPL allowed Linux operating system packagers (eg Debian) to use things that had been developed by or adapted for GNU.

Otherwise, Stallman told me he wouldn't have bothered with GNU if he'd known that BSD Unix was going to be available as free software. Unfortunately, FreeBSD wasn't released until 1993.

[1] https://www.gnu.org/gnu/initial-announcement.html

UNIX is an open standard with a certification program, and Linux certainly tries to follow the standard.

The only real reason that a Linux distribution hasn't been UNIX-certified is because RedHat and IBM found there was very little marketing value in calling it UNIX, that is, Linux is a stronger brand.

And I suspect the only reason MacOS is UNIX-certified is because they advertised it as "UNIX" and were sued by The Open Group, who owns the trademark. [1]

[1] https://www.cnet.com/news/apple-in-court-dispute-over-unix/

K-UX is Linux. It is certified. It's based on Red Hat.

There's the recursive acronym for GNU: "GNU's Not Unix!" due to GNU/Linux's Unix-like qualities. I think you can be forgiven for comparing the two :)

Let's be fair here, K-UX is running Linux, and it's certified by the Open Group.

It's based on Red Hat. It has been officially certified as UNIX by The Open Group.

OSX _is_ UNIX. It's certified to use the Single UNIX Specification markings (version 3).

And that means all the basic tools and system calls one expects on a true UNIX machine are present in OSX.

BSD is Unix-based.

Linux distribution? I think you mean *BSD distribution.

Uhh OS X is based on BSD and NeXTSTEP. As is iOS.