I think one approach in (re)designing an OS should be to go back to fundamentals: what makes an Operating System? I think fundamentally, there are only a few t

I think one approach in (re)designing an OS should be to go back to fundamentals: what makes an Operating System? I think fundamentally, there are only a few things it has to do: Allow applications to run (on the CPU/other hardware), Allow applications to communicate between themselves (establish communication standards), Allow access to disk, Manage the time given to each application well/fairly, Define permissions around resources (who can talk to whom and who can access what). Depending on who you ask, shells/desktop environments should be part of the OS too. When I think of the minimum that can accomplish that, I think something like a simple communication standard (with authentication mechanisms) would be interesting (with possibility to support more specialized standards). A standard for defining app. share of resources (CPU/disk). Maybe hardware resources like disks, devices like cameras, etc.. could be treated as applications via a driver (or application <-> disk application <-> disk driver). Then instead of 'opening' files, you're just communicating your intentions with a disk driver, and you can do essentially anything. Maybe then instead of a Filesystem Hierarchy standard, there could simply be "OS (standard) applications" that for example list what users are in the OS, what applications are available, and so on (without a filesystem hierarchy at all, if you wish!). An FHS could be provided for legacy reasons. I also think permissions should take a more fine grained approach than Unix/Linux does (closer to Android permission systems), I think by default applications should have minimum permissions and should be whitelisted as needed.