It’s easy to forget where and when macOS had its earliest origins.  Its tumultuous path had its earliest start with Steve Jobs at NeXT. « NeXTStep was developed primarily by Avie Tevanian. The coder previously worked on the Mach microkernel, a supercharged version of UNIX, at Carnegie Mellon University. Jobs convinced Tevanian to join NeXT instead of taking what, in the short term, would have been a far more lucrative job at Microsoft. » This is a nifty, concise history of how it all started.
Check It Out: The Origins of macOS: Steve Jobs and NeXTSTEP
One can still play with a version of NextStep. It’s called OpenStep. I once compiled it and ran it on my Pismo. It was… different, but so weird to see some things, like the Finder and Mail.app working in that environment.
I think it’s still available via projects like MacPorts, if one has the patience to get it running. I think many Linux distros also have it as an installable package. I heartily recommend it for anyone who wants to experience what Jobs had in mind for the future of computing in the 90s. 🙂
Now I’m embarrassed… I should have read the referenced article before posting… I see they mentioned it too. :blushing:
One feature of OpenStep I forgot to mention, and that I don’t think the article mentions is that in OpenStep (and I think NextStep), you could tear off menus and keep them on the screen. Very useful for some tools you were using a lot at the moment. (For instance, you could keep the « Edit » menu on screen for quick copying and pasting, or the Font menu for quick experimentation.)