MacOS
operating system for Apple computers
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).
The public source identifies “MacOS” as operating system for Apple computers. This brief keeps that definition visible, then builds a research path around MacOS, operating and system.
Why this record matters
A short description can identify a subject without explaining its stakes. For “MacOS”, the useful work is to connect “operating system for Apple computers” to the records capable of establishing context and consequence.
Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Sep 23, 2026. The linked authority identifier is Q14116. VIAF identifies the subject as 8146152942405251549. The Library of Congress control number is n96060065. 2 of 10 selected statements include explicit references; 6 carry qualifiers and 1 use preferred rank. The first chronological checks are 2001, 2026, 1984 and 2025.
Overview language is designed for orientation and should not be treated as a substitute for the evidence cited beneath it. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “MacOS”, its source revision and the description used here.
- Expand the search: follow MacOS primary sources, MacOS archive and MacOS research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “MacOS”?
- What terminology or title could unlock a more precise catalogue search?
- Which institution is responsible for the underlying evidence?
Search terms from this dossier
This entry incorporates text from “MacOS” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.