It's a pretty loaded question, I'm not sure you'd even have wide agreement on what Unix is. Are we talking about kernels? The general design philosophy? The bro

It's a pretty loaded question, I'm not sure you'd even have wide agreement on what Unix is. Are we talking about kernels? The general design philosophy? The broader ecosystem? For example, the failure of Unix like systems to deliver anything interesting in the GUI/PC space. One may say that's a Unix failure, but it may make more sense to say it's a failure of open source software. It's certainly not as if the kernel design or the OS philosophy is what hindered developing useful GUI software. And then you have to ask if OS X counts as a Unix or not. Does Android? Speaking in very broad philosophical terms disregarding practical concerns, I really love the Lisp Machine/Genera [0] model. Today somewhat represented by Emacs. Most modern OSes operate under a black box model. They're just runtimes for siloed software. On Linux, the kernel, window managers and pretty much everything might be open source. But even for a highly technical power user these things are as impenetrable and unchangeable as, say, Windows proprietary software. I don't think there's even that many fundamental disagreements between Windows and Unix. Most divergences are best explained by Microsoft's relentless end-user orientation. In the Emacs model there's very little delineation between anything really. Not just system vs "user space", but between "user space" packages themselves. Everything is just code running in the same environment. The system is an IDE unto itself. One may say Emacs isn't a real operating system (it's not) and perhaps Genera wouldn't be either by modern standards. But I'm not sure that's all there is to it. Most modern programming languages tend to replicate the siloed model too. Even highly dynamic non-OO languages like JavaScript pretty much went with a blackbox library model. It does seem like a general computing principle, rather than something that's only relevant at a given level. There are severe practical limitations, but I don't think it's a super niche thing with no appeal. I'd say no-code tools, app builders, website creators etc play into something similar. Or how people love using Excel for all sorts of back office stuff. Every few years some vaporware makes a lot of noise promising everybody will be able to create great software with their tool. There's certainly a need for malleability. [0] Don't take my word on what Lisp Machines were exactly. I don't have any direct experience with them. If what I read about them is wrong, substitute for just Emacs and the comment still stands.