Architecture of macOS

This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these messages) This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Architecture of macOS" – news · newspapers · books · scholar · JSTOR (January 2018) (Learn how and when to remove this message) This article needs to be updated. Please help update this article to reflect recent events or newly available information. (January 2018) (Learn how and when to remove this message)

The architecture of macOS describes the layers of the operating system that is the culmination of Apple Inc.'s decades-long research and development process to replace the classic Mac OS.

After the failures of their previous attempts—Pink, which started as an Apple project but evolved into a joint venture with IBM called Taligent, and Copland, which started in 1994 and was cancelled two years later—Apple began development of Mac OS X, later renamed OS X and then macOS, with the acquisition of NeXT's NeXTSTEP in 1997.