2001 · Apple Inc.

MacOS

operating system for Apple computers

Released: 24 March 2001
Platforms: PowerPC x86 x86-64
Genres: —
Developers: Apple Inc.
Publishers: —
Series: XNU FreeBSD Unix

About

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. 0, was released on March 24, 2001. Apart from OS X Lion, all versions from Mac OS X Leopard onwards are UNIX 03 certified.

The articlegameplay, story, development, reception

Development

The heritage of what would become macOS originated at NeXT, a company founded by Steve Jobs following his departure from Apple in 1985. There, the Unix-like NeXTSTEP operating system was developed, before being launched in 1989. The kernel of NeXTSTEP is based upon the Mach kernel, which was originally developed at Carnegie Mellon University, with additional kernel layers and low-level user space code derived from parts of FreeBSD and other BSD operating systems. Its graphical user interface was built on top of an object-oriented GUI toolkit using the Objective-C programming language.

Throughout the 1990s, Apple had tried to create a "next-generation" OS to succeed its classic Mac OS through the Taligent, Copland and Gershwin projects; however, all were eventually abandoned. This led Apple to acquire NeXT in 1997, allowing NeXTSTEP, later called OPENSTEP, to serve as the basis for Apple's next-generation operating system.

Reception

As of January 2023, macOS is the second-most widely used general-purpose desktop operating system used on the World Wide Web following Microsoft Windows, with a 15.33% usage share, according to statistics compiled by StatCounter.

As a hardware company, Apple has mostly promoted macOS to sell Macs, with promotion of macOS updates focused on existing users, promotion at Apple Store and other retail partners, or through events for developers. In larger scale advertising campaigns, Apple specifically promoted Mac OS X/macOS as better for handling media and other home-user applications, and comparing Mac OS X (especially versions such as Tiger and Leopard) with the heavy criticism Microsoft received for the long-awaited Windows Vista operating system.