ReactOS

Why is it so difficult to build a non-Microsoft OS that runs Windows software natively?

Why can't someone create an operating system that runs Windows applications directly, while avoiding the rest of Microsoft's ecosystem? I understand that compatibility tools such as Wine and…

Why is it so difficult to run Windows software natively on another operating system?

What prevents someone from creating a non-Microsoft operating system that can run Windows programs directly, without relying on compatibility layers? I understand that projects such as Wine and…