The foundational software upon which Apple’s mobile operating system relies is a subject of ongoing discussion. While it shares a common ancestor with Unix-like systems, the core is based on XNU, a hybrid kernel developed by Apple. This kernel incorporates elements from Mach, a microkernel developed at Carnegie Mellon University, and components from BSD, a Unix-like operating system.
Understanding the lineage of operating systems provides insight into their architectural choices and development paths. Examining the evolution from Unix to BSD, and the subsequent divergence into macOS (formerly OS X) and iOS, illustrates the complex interplay of open-source contributions and proprietary innovation. The performance characteristics, security model, and available functionalities are all influenced by these fundamental design decisions.
