"An OS is the thing in about Linux (kernel) scope" I'm using the standard street definition in which the OS is everything that you get on a fresh (desktop) OS

"An OS is the thing in about Linux (kernel) scope" I'm using the standard street definition in which the OS is everything that you get on a fresh (desktop) OS install, not just the kernel. There's very little research available on kernels because their shape is largely dictated by the hardware design, and the hardware design is largely dictated by physics and what the manufacturers give us. But as you go further up the stack the options widen considerably. You can start to consider user interfaces, application programming models, etc. "You just need to build capability security into CPUs, the OS, and all apps…" Pure cap systems are an old idea that have never worked. They're too cumbersome for programmers and affect API design in problematic ways. But here's the thing. If you disagree, you can go ahead and prove it. You don't need a custom CPU. Figure out the higher level software issues first, and if you ever get to the point of needing actual CPU changes then fork qemu and virtualize your intended design. Make it so custom hardware is just an optimization once the core ideas are worked out. That's what I mean by doing stuff at a higher layer. The interesting and tractable problems are all at the level where you can just throw up a fullscreen window, use direct IO to grab a block of disk space and off you go. Start from the top and work down, not bottom and work up. BTW you'd probably like the Mill architecture. It tackle a lot of the things you're talking about. Comes out of the commercial world though, not academia.