Yep. Also, a lot of kernel code originates from Mach via NeXTStep. Some parts of the userland are from NetBSD as well. It's really a mixture of Mach, FreeBSD,

Yep. Also, a lot of kernel code originates from Mach via NeXTStep. Some parts of the userland are from NetBSD as well. It's really a mixture of Mach, FreeBSD, NetBSD, GNU and Apple's own additions and modifications. So, the I guess the only proper names for this beast are XNU and Darwin.