MAC OS X

macOS

Screenshot of the latest version of macOS, Sierra (10.12), as of September 2016[update]
Developer	Apple
Written in	C C++ Objective-C Swift
OS family	Macintosh, Unix
Working state	Current
Source model	Closed source (with open source components)
Initial release	March 24, 2001; 15 years ago (2001-03-24)
Latest release	10.12.3 (16D32) (January 23, 2017; 13 days ago (2017-01-23))
Marketing target	Personal computing
Available in	34 languages
List of languages  As of macOS Sierra: Arabic, Catalan, Croatian, Chinese (Simplified), Chinese (Traditional), Czech, Danish, Dutch, English, Finnish, French, German, Greek, Hebrew, Hungarian, Indonesian, Italian, Japanese, Korean, Malay, Norwegian, Polish, Portuguese (Brazil), Portuguese (Portugal), Romanian, Russian, Slovak, Spanish (Mexico), Spanish (Spain), Swedish, Thai, Turkish, Ukrainian, Vietnamese
Update method	Mac App Store (10.8+) Software Update (10.0–10.7)
Platforms	x86-64 (10.4.7+) IA-32 (10.4.4–10.6.8; discontinued) PowerPC (10.0–10.5.8; discontinued)
Kernel type	Hybrid (XNU)
Default user interface	Graphical (Aqua)
License	Commercial software, proprietary software
Preceded by	Classic Mac OS
Official website	www.apple.com/macos

macOS (pronounced /ˌmækoʊɛs/; previously Mac OS X, then simply OS X) is the current series of Unix-based graphical operating systems developed and marketed by Apple Inc. designed to run on Apple's Macintosh computers, having been preinstalled on all Macs since 2002. Within the market of desktop, laptop and home computers, and by web usage, it is the second most widely used desktop OS after Microsoft Windows.

Launched in 2001, as Mac OS X, the series is the latest in the family of Macintosh operating systems. Mac OS X succeeded the "classic" Mac OS, which was introduced in 1984, and the final release of which was Mac OS 9 in 1999. An initial, early version of the system, Mac OS X Server 1.0, was released in 1999. The first desktop version, Mac OS X 10.0, followed in March 2001. In 2012, Apple rebranded Mac OS X to OS X. Releases were code named after big cats from the original release up until OS X 10.8 Mountain Lion. Beginning in 2013 with OS X 10.9 Mavericks, Apple names macOS releases after landmarks in California. In 2016, Apple rebranded OS X to macOS, adopting the nomenclature that it uses for their other operating systems, iOS, watchOS, and tvOS. The latest version of macOS is macOS 10.12 Sierra, which was publicly released in September 2016.