Let's start off with defining what an Operating System really is because depending on where you draw that line the outcome will be substantially different. Ignoring mainframes and other large installations for the moment, strictly from a 'personal computer' point of view:
If you see the operating system as the task-schedular + IPC clearinghouse then the system is simple, well defined and it can be expected to perform in a deterministic and verifiably correct way (assuming working hardware).
If you define the operating system as 'everything and the kitchen sink' including media players, browsers and so on then there is no way to make any guarantees and determinism is going to be impossible to achieve.
Personally I prefer the leaner-and-meaner operating systems that have a larger ring of userland software built on top of them to create as small as possible a core on which the actual end-user applications are run.
Those systems tend to find good middle ground between reliability, speed and security because the amount of surface area exposed is going to be the minimum at every level.
Something like Windows is on one end of that scale, something like MacOS is somewhere in the middle. Linux can be stripped (or more accurately: it could be stripped) to something a lot slimmer than the default distros, and something like IRIX (no longer used in production as far as I know) was roughly where MacOS sat (custom hardware, custom OS tied closely to that hardware).
An ideal OS that limits itself to scheduling and IPC is currently not on the market for desktop usage, and the arrival of the mobile device market has blurred many of the lines that we thought were drawn pretty clearly in the past.
The 'lets move everything into the kernel' philosophy is as far as I'm concerned fatally broken and likely things will have to get a lot worse before they will finally get better, and it would not surprise me if everything that we do today will be discarded once that happens.
Where do you rate the part of the OS that makes 100,000 types, brands, and models of devices all look about the same to our apps? I always saw hardware compatibility and abstraction as the greatest value proposition, not only for the user but for the PC industry as a whole.
If you see the operating system as the task-schedular + IPC clearinghouse then the system is simple, well defined and it can be expected to perform in a deterministic and verifiably correct way (assuming working hardware).
If you define the operating system as 'everything and the kitchen sink' including media players, browsers and so on then there is no way to make any guarantees and determinism is going to be impossible to achieve.
Personally I prefer the leaner-and-meaner operating systems that have a larger ring of userland software built on top of them to create as small as possible a core on which the actual end-user applications are run.
Those systems tend to find good middle ground between reliability, speed and security because the amount of surface area exposed is going to be the minimum at every level.
Something like Windows is on one end of that scale, something like MacOS is somewhere in the middle. Linux can be stripped (or more accurately: it could be stripped) to something a lot slimmer than the default distros, and something like IRIX (no longer used in production as far as I know) was roughly where MacOS sat (custom hardware, custom OS tied closely to that hardware).
An ideal OS that limits itself to scheduling and IPC is currently not on the market for desktop usage, and the arrival of the mobile device market has blurred many of the lines that we thought were drawn pretty clearly in the past.
The 'lets move everything into the kernel' philosophy is as far as I'm concerned fatally broken and likely things will have to get a lot worse before they will finally get better, and it would not surprise me if everything that we do today will be discarded once that happens.