Mac OS X is the newest and most prominent of Apple Computer's Mac OS line of operating systems, however the Mac OS X history can be traced back to the 1960s -- to UNIX, to BSD, and most significantly to NeXT's OPENSTEP, Mac OS X's direct ancestor.

There are four main paths that can be followed to trace back the history:

Table of contents
1 The politics game
2 From the operating system view
3 From the GUI perspective
4 From the language/third party developer perspective
5 Bringing it all together

The politics game

When Apple fired Steve Jobs in 1985, he immediately proceeded, with funding from Ross Perot and his own pockets, to aim to create the next great thing: the result was NeXT. NeXT hardware, while somewhat innovative for its time, was overly expensive in relation to the rapidly commoditizing workstation market, and was phased out in 1993. The NeXTSTEP operating system, on the other hand, received significant critical acclaim and a wide following, and gave birth to the groundbreaking Enterprise Objects Framework database access layer and WebObjects application server development environment. NeXT managed to maintain a business selling WebObjects and consulting services, but was never a commercial success.

But in 1996, Apple did not seem to be a success either. The company was desperate for a new operating system, and after briefly flirting with BeOS decided to acquire NeXT. Avie Tevanian took over OS development, leading the Rhapsody project to transform the NeXT operating system into the next generation Mac OS while Steve Jobs was brought on as a consultant. Apple continued to bleed red ink, though, and eventually Steve persuaded the existing board to fire Gil Amelio, and appoint him Chairman and interim CEO. Jobs was, in essence, given carte blanche by the Apple board to both return the company to profitability and to lead the search for a new CEO

Apple's key personnel and the company's hardware and software plans were completely revamped by Jobs, and the NeXT influence could have scarcely been greater. NeXT's software engineers began the task of transforming their workstation-centric operating system into something suitable for Apple's humanist following, and Rhapsody in 1998 became Mac OS X. After a couple of years, Steve Jobs decided to stay with the newly-profitable Apple as full-time CEO. In the meantime, Mac OS X made Apple the world's most prolific distributor of UNIX-based operating systems and, along with innovative new products like the iMac, spearheaded Apple's return to long-term success.

From the operating system view

In 1986, NeXT was developing a product based on the Mach kernel and BSD, NeXTSTEP, later to become OPENSTEP, whereas Apple was concentrating on recovering from the Apple Lisa not being the commercial success they thought it was, and were concentrating on promoting its lower cost Macintosh line just to survive. NeXTSTEP was eventually ported from 68k to the Intel platform (and prototypes existed for SPARC, PA-RISC, and even Motorola 88k ports), and rechristened as the OS-independent OpenStep which ran on x86 and (briefly) SPARC, but never really caught on.

In mid 1997, with Jobs back onboard, he was fully responsible for getting the Apple team up to date on incorporating NeXT technologies into Apple over 4 years. Apple sold OpenStep for awhile while developing Rhapsody, the OpenStep-based next-generation Macintosh operating system. In 1998, Steve Jobs, now CEO, announced that the Rhapsody project had become Mac OS X. In January of 1999, Apple released their first Mac OS X product, Mac OS X Server 1.0. A public beta of Mac OS X was released in 2000 and March 21, 2001, saw the full and official release of Mac OS X version 10.0. Version 10.1 shipped a few months later, followed by the 2002 release of Mac OS X Jaguar (10.2) and the 2003 release of Mac OS X Panther (10.3).

From the GUI perspective

Practically since its inception, Apple was seen to stress innovation in its products. Starting in 1980, after some visits to Xerox PARC, Apple set out to have its own GUI based computing environment. By 1984, Apple had split its resources, and developed two GUI based operating systems, the lower cost Macintosh (the team that Jobs headed), and the more robust and professional Lisa, which failed in the marketplace. Again, after restabilizing in 1986, Apple developed, through research and trial-and-error, a set of human interface guidelines, with its first release as a book . Apple continued to focus much of its effort on creating a usable operating system, to the point where it was seen by some to lose strength because of its lack of professional features. Nonetheless, when it came time for OSX, Apple poured on its experience in GUI and usability design. While Mac OS X Server 1.0 used a modified version of the Mac OS GUI, Mac OS X Public Beta and later used a new GUI known as Aqua.

From the language/third party developer perspective

Now, C, C++, Objective C, Java, and Python can be used to program OS X natively. Adding industry standards like Java and Python only furthered this comfort. The effects of Apple's incorporations into OS X resulted in some interesting views by software developers; contrasted with Microsoft, which completely develops its own languages or variants thereof, Apple's choice was perceived to be more elegant.

Bringing it all together

Apple developed its GUI/usability experience as much as its systems experience (and that of NeXT's) into making OS X.

By relying on NeXT and BSD, on Objective C, and staying true to the BSD spirit of keeping things open, Apple has mixed its conservative decision to go with well developed components with a relatively cautious approach toward the power of the open source community to further its maintainability and acceptance in the world. Apple however was under criticism for its licensing scheme to software components, that their open source licensing scheme, the Apple Public Source License (APSL) did not live up to the standards of open source software. However several components' source of the Darwin core OS subsystem of Mac OS X is available.

Shortly after Apple rewrote the APSL. Now version 2 remains as one of the approved licenses of the Open Source Initiative (OSI), however, the Free Software Foundation do not recommend its use for developers but improving software under the APSL is viewed to be satisfactory.

See also: Mac OS history