Hybrid Kernel - Examples - NT Kernel

NT Kernel

The best known example of a hybrid kernel is the Microsoft NT kernel that powers all operating systems in the Windows NT family, up to and including Windows 7 and Windows Server 2008 R2, Windows 8 and Windows Server 2012, and will be powering Windows Phone 8. NT-based Windows is classified as a hybrid kernel (or a macrokernel) rather than a monolithic kernel because the emulation subsystems run in user-mode server processes, rather than in kernel mode as on a monolithic kernel, and further because of the large number of design goals which resemble design goals of Mach (in particular the separation of OS personalities from a general kernel design). Conversely, the reason NT is not a microkernel system is because most of the system components run in the same address space as the kernel, as would be the case with a monolithic design (in a traditional monolithic design, there would not be a microkernel per se, but the kernel would implement broadly similar functionality to NT's microkernel and kernel-mode subsystems).