XNU
Legacy mirror of Darwin Kernel
Darwin XNU is the hybrid kernel that powers Apple’s macOS, iOS, watchOS, and tvOS operating systems, forming the foundation of the Darwin open-source core. The name XNU stands for X is Not Unix, highlighting its origin as a combination of multiple kernel technologies—primarily the Mach microkernel from Carnegie Mellon University, integrated with substantial components from FreeBSD and Apple’s proprietary IOKit driver framework. This hybrid architecture merges the microkernel model’s message...