# XNU **Domain:** Operating Systems / Kernel Architecture **Doc Type:** Technical Platform Node **Maturity:** Deployed **Primary Source:** [[articles/The Art is Long|The Art is Long: Vespucci of Immortality]] **Related:** [[wiki/Mach Kernel|Mach Kernel]], [[wiki/NEXTSTEP|NEXTSTEP]], [[wiki/NeXT|NeXT]], [[wiki/Darwin Bioinformatics Environment|Darwin Bioinformatics Environment]] --- ## Definition **XNU** is the kernel at the core of Apple's Darwin operating-system platform. Its architecture joins Mach-derived mechanisms with BSD process and networking semantics and the I/O Kit device-driver framework. ## Historical Lineage The relevant lineage is NEXTSTEP/OPENSTEP → Rhapsody → Mac OS X → Darwin/XNU. This preserves the material inheritance from NeXT while avoiding the inaccurate shorthand that NEXTSTEP itself became Darwin. ## Sources / Provenance - [Apple open-source XNU repository](https://github.com/apple/darwin-xnu).