Alt text: meme with the ‘Always has been’ format Linux, MacOS, OpenBSD and ChromeOS logos on top of the Earth The first astronaut says ‘Wait, it’s all Unix?’ A Windows logo, on top of the second astronaut. The second astronaut says ‘Always has been’ and points a gun to the first astronaut.
Half of those are Unix-like. Don’t forget what GNU stands for (literally, not philosophically)!
To be fair, iirc, macOS is certified UNIX despite having the XNU kernel which stands for X is Not UNIX.
Certified? Are you saying it’s POSIX?
Nah, Windows is the weird one.
And it should be Unix-like.
Linux is unix-like, and not from the same family really. ChromeOS is based on linux, so similarly unix-like. Mac is Darwin, which is actually unix. Also all BSDs are unix
BSD is also unix-like. Quoting OpenBSD, “[OpenBSD] produces a FREE , multi-platform 4.4BSD-based UNIX-like operating system.”
Nice to know, I’ve always thought BSD is actually UNIX.
The BSD variants are descendants of UNIX developed by the University of California at Berkeley, with UNIX source code from Bell Labs. However, the BSD code base has evolved since then, replacing all the AT&T code. Since the BSD variants are not certified as compliant with the Single UNIX Specification, they are referred to as “UNIX-like” rather than “UNIX”.
UNIX™ is a trademark name (Think of e.g. IBM AIX, HP-UX, SunOS). Linux and BSD are Unix alike. I believe that Apple has made an effort to be entitled to call an OS of theirs UNIX, not sure whether it’s Darwin or something else.
UNIX is trademarked by ‘The Open Group’, Unix is not. 🙃
To make things more confusing, according to German Wikipedia, Unix is used for Unix-like OSes which are not officially UNIX-certified. 😵💫