MacOS

macOS (previously OS X and originally Mac OS X) is a proprietary Unix operating system, derived from OPENSTEP for Mach and FreeBSD, which has been marketed and developed by Apple since 2001. It is the current operating system for Apple's line of Mac computers. As of April 2026, within the market of desktop and laptop computers, it is the second most widely used desktop OS, after Microsoft Windows and ahead of all Linux distributions, including ChromeOS and SteamOS. As of 2026, the most recent release of macOS is macOS 27 Golden Gate, the 23rd major version of macOS. Mac OS X succeeded the classic Mac OS, the primary Macintosh operating system from 1984 to 2001. Its underlying architecture came from NeXT's NeXTSTEP, as a result of Apple's acquisition of NeXT, which also brought Steve Jobs back to Apple. The first desktop version, Mac OS X 10.0, was released on March 24, 2001. Apart from OS X Lion, all versions from Mac OS X Leopard onwards are UNIX 03 certified. Each of Apple's other contemporary operating systems, including iOS, iPadOS, watchOS, tvOS, audioOS and visionOS, are derivatives of macOS. During its history, macOS has supported three major processor architectures: the initial version supported PowerPC-based Macs only, with support for Intel-based Macs beginning with Mac OS X Tiger 10.4.4 and support for ARM-based Apple silicon Macs beginning with macOS Big Sur. Support for PowerPC-based Macs was dropped with Mac OS X Snow Leopard, and it was announced at the 2025 Worldwide Developers Conference that macOS Tahoe will be the last to support Intel-based Macs. Unlike versions of the classic Mac OS, Mac OS X retained the same major version number (10) for almost two decades, with major releases only incrementing the minor version number (e.g. 10.5 → 10.6). Since 2020, Apple increments...