macOS

macOS, previously OS X and originally Mac OS X, is a <a href="/facts/Unix/0pNL2seI">Unix-based</a> <a href="/facts/Operating_system/8XTuvMh2">operating system</a> developed and marketed by <a href="/facts/Apple_Inc./oTJYta3k">Apple</a> since 2001. It is the current operating system for Apple's <a href="/facts/Mac_(computer)/8GhnXTK0">Mac computers</a>. Within the market of <a href="/facts/Desktop_computer/edFPINdK">desktop</a> and <a href="/facts/Laptop/3EFwTAb2">laptop</a> computers, it is the <a href="/facts/Usage_share_of_operating_systems/zcuukwfc">second most widely used desktop OS</a>, after <a href="/facts/Microsoft_Windows/bwhAhuSL">Microsoft Windows</a> and ahead of all <a href="/facts/Linux/9FvCKSTq">Linux</a> distributions, including <a href="/facts/ChromeOS/zH0B5Xtk">ChromeOS</a> and <a href="/facts/SteamOS/fL2Je1Ge">SteamOS</a>. As of 2024, the most recent release of macOS is <a href="/facts/MacOS_Sequoia/aMftEP5V">macOS 15 Sequoia</a>, the 21st major version of macOS.
Mac OS X succeeded <a href="/facts/Classic_Mac_OS/I5fQq44K">classic Mac OS</a>, the primary <a href="/facts/Mac_operating_systems/EkobAhow">Macintosh operating system</a> from 1984 to 2001. Its underlying architecture came from <a href="/facts/NeXT/71CK18lB">NeXT</a>'s <a href="/facts/NeXTSTEP/BtVf9f5t">NeXTSTEP</a>, as a result of <a href="/facts/NeXT/71CK18lB">Apple's acquisition of NeXT</a>, which also brought <a href="/facts/Steve_Jobs/fQpja1hx">Steve Jobs</a> back to Apple. The first desktop version, <a href="/facts/Mac_OS_X_10.0/twuQ9J75">Mac OS X 10.0</a>, was released on March 24, 2001. <a href="/facts/Mac_OS_X_Leopard/UmXw4H5x">Mac OS X Leopard</a> and all later versions of macOS, other than <a href="/facts/OS_X_Lion/CHyxXg8X">OS X Lion</a>, are <a href="/facts/UNIX_03/w1ba5bDt">UNIX 03</a> certified. The derivatives of macOS are Apple's other operating systems: <a href="/facts/IOS/mK5cggH5">iOS</a>, <a href="/facts/IPadOS/fClrmH7D">iPadOS</a>, <a href="/facts/WatchOS/zH1fkn2R">watchOS</a>, <a href="/facts/TvOS/jDMqvvfI">tvOS</a>, <a href="/facts/AudioOS/ToJVXQMc">audioOS</a> and <a href="/facts/VisionOS/2Igexrxe">visionOS</a>. macOS has supported three major processor architectures: originally <a href="/facts/PowerPC/DqmM9y50">PowerPC</a>-based Macs in 1999; <a href="/facts/Apple%25E2%2580%2593Intel_architecture/1GpN0gWz">Intel Core-based Macs</a> from <a href="/facts/Apple_transition_to_Intel/uJTbuLvM">2006</a>; and self-designed <a href="/facts/AArch64/bauXRos7">64-bit Arm</a> <a href="/facts/Apple_M_series/A8RgouDB">Apple M series</a> Macs since <a href="/facts/Mac_transition_to_Apple_silicon/66tIrRs2">2020</a>.
A prominent part of macOS's original <a href="/facts/Brand_identity/hP6SnDWU">brand identity</a> was the use of <a href="/facts/Roman_numerals/7BA8nn78">Roman numeral</a> X, pronounced "ten", as well as <a href="/facts/Code_name/MRq0mo4b">code naming</a> each release after species of <a href="/facts/Big_cat/KFjIPS7F">big cats</a>, and later, places within <a href="/facts/California/zLW2vdQJ">California</a>. Apple shortened the name to "OS X" in 2011 and then changed it to "macOS" in 2016 to align with the branding of Apple's other operating systems. In 2020, <a href="/facts/MacOS_Big_Sur/RV8pCK4d">macOS Big Sur</a> was presented as version 11—a marked departure after 16 releases of macOS 10—but the naming convention continued to reference places within California. In 2025, Apple unified the <a href="/facts/Software_versioning/EP8VXAUU">version number</a> across all of its products to align with the year after their WWDC announcement, so the release announced at the 2025 WWDC, <a href="/facts/MacOS_Tahoe/UFzk2JMk">macOS Tahoe</a>, is macOS 26.

macOS open-in-new

macOS