In computer science, a nanokernel is a very minimalist operating system kernel. The nanokernel represents the closest hardware abstraction layer of the operating system by interfacing the CPU, managing interrupts and interacting with the MMU. The interrupt management and MMU interface are not necessarily part of a nanokernel; however, on most architectures these components are directly connected to the CPU, therefore, it often makes sense to integrate these interfaces into the kernel.

a species of korn

The lowest-level part of the system software for PowerPC processor-based Macintosh computers.