As a retired software engineer who worked for 40 years in operating systems kernels and low level stuff, the idea of simply emulating the OSx or Windows (any version) kernel in a new system and running all the apps like Quicken, PhotoShop, Adobe is a fantasy. The APIs are not that well documented and programs tend to depend on little oddities which are not 'official', and then 'emulators' don't perform the oddity, and the app doesn't run. People try to do it, but it's nothing a casual user is going to put up with. Nothing wrong with coming up with a new system, but it is definitely not trivial. Do you have any idea how may million lines of code there in a modern OS? Get a grip.