> At this point, they could likely decompile MacOS classic and rework it to give it modern memory protection, virtual memory, preemptive multitasking, and networking.

You'd lose compatibility with the applications, though, so you'd have to decompile and rework those as well. And even if you did, you couldn't legally distribute any of it.

An alternative approach is high-level emulation. Running a separate instance per application gives you process isolation (via the host OS) for free.

> I assume booting an OS with a mere few megabytes of RAM footprint would only take milliseconds?

I haven't measured it as such, but yes.

> they could likely decompile MacOS classic and rework it to give it modern memory protection, virtual memory, preemptive multitasking, and networking.

It had most if not all of that.

It had networking from the start with AppleTalk, later Ethernet and internet with MacTCP.

MacOS 9 had a preemptively scheduled kernel.

The problem is having that and supporting the software ecosystem, which depended on cooperative scheduling without having memory protection.

MacOS 9 ‘solved’ that by running the classic OS in a single process. It had APIs for creating preemptively scheduled threads, but those threads were limited in what they could do.

I am in the middle of doing this with apple's System 6 and adding a posix-compliant shell under the codename bluetail, and working my way up, i've got it booting with an os, busybox, openssh and stuff. Boots on a raspberry pi 3 A+ bare metal (And qemu, of course). And full usb MIDI support, because (I said so, and) there's actually an incredible catalog of early DAW software that will run on System 6. And pretty decent usb ethernet, sound, webcam etc etc. The future of hobby software is wild.

> Mmm. Or improve the OSes themselves.

Haiku specifically does not accept AI-generated code.

I expect if you use AI to explain how to write it and then write it yourself that would be okay.

You need to be able to explain your work without just pasting in what Special Needs Wintermute says.