ExectOS is a preemptive, reentrant multitasking operating system that implements the XT architecture which derives from NT architecture. It is modular, and consists of two main layers: microkernel and user modes. Its’ kernel mode has full access to the hardware and system resources and runs code in a protected memory area. It consists of executive services, which is itself made up on many modules that do specific tasks, a kernel and drivers. Unlike the NT, system does not feature a separate Hardware Abstraction Layer (HAL) between the physical hardware and the rest of the OS. Instead, XT architecture integrates a hardware specific code with the kernel. The user mode is made up of subsystems and it has been designed to run applications written for many different types of operating systems. This allows us to implement any environment subsystem to support applications that are strictly written to the corresponding standard (eg. DOS, or POSIX). Thanks to that ExectOS will allow to run existing software, including Win32 applications.
↫ ExectOS website
What ExectOS seems to be is an implementation very close to what Windows NT originally was – implementing the theory of Windows NT, not the reality. It’s clearly still in very early development, but in theory, I really like the idea of what they’re trying to achieve here. Windows NT is, after all, in and of itself not a bad concept – it’s just been tarred and feathered by decades of mismanagement from Microsoft. Implementing something that closely resembles the original, minimalist theories behind NT could lead to an interesting operating system for sure.
ExectOS is open source, contains its own boot loader, only runs on EFI, and installation on real hardware, while technically possible, is discouraged.