Yes and no. The macOS kernel is a hybrid kernel, containing three major subsystems: * Core IPC is from Carnegie-Mellon's Mach microkernel. * Interprocess c

Yes and no. The macOS kernel is a hybrid kernel, containing three major subsystems: * Core IPC is from Carnegie-Mellon's Mach microkernel. * Interprocess communication and virtual file system APIs from BSD. * A custom driver API written in C++ called IOKit. However, the kernel is probably the least interesting part of your computer; what users consider the ‘operating system’ lies in the user land. As long as the kernel works and supports your hardware devices, you needn't care. As an example, both FreeBSD and Windows can pretend to be a Linux kernel and run a nearly complete GNU user land, and multiple quite different user lands exist on top of the Linux kernel, the most prominent being Android and the GNU tools.