Mac OS From Wikipedia , the free encyclopedia "MacOS" redirects here. For the American humanities teaching program, see Man: A Course of Study . Mac OS Screenshot of Mac OS 10.10 Yosemite Company / developer Apple , Steve Jobs OS family Classic Mac OS ( System 1–7, Mac OS 8–9) Unix , Mach and FreeBSD ( OS X ) [1] [2] [3] Working state Publicly released Source model Proprietary software (with open-source components) Initial release January 24, 1984 ; 30 years ago Latest release 10.9.4 (Build 13E28) [4] (June 30, 2014 ; 15 days ago ) [±] Latest preview 10.10 (Build 14A283o) (July 7, 2014 ; 8 days ago ) [±] Kernel type Hybrid ( XNU ) License Commercial Official website apple.com/osx/ Mac OS is a series of graphical user interface -based operating systems developed by Apple Inc. for their Macintosh line of computer systems . The original version was integral and an unnamed system software first introduced in 1984 w