Benutzer:Felicior/Versionsgeschichte von MacOS
Mac OS X is the newest of Apple Computer's Mac OS line of operating systems. Although it is officially designated as simply "version 10" of the Mac OS, it has a history largely independent of the earlier Mac OS releases.
Development outside of Apple
After Apple removed Steve Jobs from management in 1985, he left the company and attempted — with funding from Ross Perot and his own pockets — to create the "next big thing": the result was NeXT. NeXT hardware was somewhat innovative for its time, but it had several quirks and design problems and was expensive compared to the rapidly-commoditizing workstation market. It was phased out in 1993. However, the company's object-oriented operating system NeXTSTEP had a more lasting legacy.
NeXTSTEP was based on the Mach kernel and BSD, an implementation of Unix dating back to the 1970s. Perhaps more remarkably, it featured an object-oriented programming framework based on the Objective-C language. This environment is known today in the Mac world as Cocoa. It also supported the innovative Enterprise Objects Framework database access layer and WebObjects application server development environment, among other notable features.
All but abandoning the idea of an operating system, NeXT managed to maintain a business selling WebObjects and consulting services, but was never a commercial success. NeXTSTEP underwent an evolution into OPENSTEP which separated the object layers from the operating system below, allowing it to run with less modification on other platforms. OPENSTEP was, for a short time, adopted by Sun Microsystems. However, by this point, a number of other companies — notably Apple, IBM, Microsoft, and even Sun itself — were claiming they would soon be releasing similar object-oriented operating systems and development tools of their own. (Some of these efforts, such as Taligent, did not fully come to fruition; others, like Java, gained widespread adoption.)
Internal development
Meanwhile, Apple was facing commercial difficulties of its own. The decade-old Mac OS had reached the limits of its single-user, co-operative multitasking architecture, and its once-innovative user interface was looking increasingly "dated." A massive development effort to replace it, known as Copland, was started in 1994, but was generally perceived outside of Apple to be a hopeless case due to political infighting. By 1996 Copland was nowhere near ready for release, and the project was eventually cancelled. Some elements of Copland were incorporated into Mac OS 8, released in 1997.
After considering the purchase of BeOS — a multimedia-enabled, multi-tasking OS designed for hardware similar to Apple's — the company decided instead to acquire NeXT and use OPENSTEP as the basis for their new OS. Avie Tevanian took over OS development, and Steve Jobs was brought on as a consultant. At first, the plan was to develop a new operating system based almost entirely on an updated version of OpenStep, with an emulator — known as the Blue Box — for running "classic" Macintosh applications. The result was known by the code name Rhapsody, slated for release in late 1998.
Apple expected that developers would port their software to the considerably more powerful OpenStep libraries once they learned of its power and flexibility. Instead, the vast majority of developers told Apple that this would never occur, and that they would rather leave the platform entirely. This "rejection" of Apple's plan was largely the result of a string of previous broken promises from Apple; after watching one "next OS" after another disappear and Apple's marketshare dwindle, developers were not interested in doing much work on the platform at all, let alone a re-write.
Changed direction under Jobs
Apple's financial losses continued, and eventually Jobs persuaded the board of directors to fire CEO Gil Amelio and appoint him Chairman and interim CEO. Jobs was, in essence, given carte blanche by the Apple board to return the company to profitability. When Jobs announced at the World Wide Developer's Conference that what developers really wanted was a modern version of the Mac OS, and that's what Apple was going to deliver, it was met with thunderous applause. Over the next two years, major effort was applied to porting the original Macintosh APIs to Unix libraries known as Carbon. Mac OS applications could be ported to Carbon without the need for a complete re-write, while still making them full citizens of the new operating system. Meanwhile, applications written using the older toolkits would be supported using the "Classic" Mac OS 9 emulator. Included support for C, C++, Objective-C, Java, and Python furthered developer comfort.
During this time the lower layers of the operating system (the Mach kernel and the BSD layers on top of it) were re-packaged and released under an open source license as Darwin. The Darwin kernel provides an extremely stable and flexible operating system, which rivals many other Unix implementations, and takes advantage of the contributions of programmers and independent open-source projects outside of Apple; however, it sees little use outside the Macintosh community. During this period, the Java programming language had increased in popularity, and an effort was started to improve Mac Java support. This consisted of porting a high-speed Java virtual machine to the platform, and exposing OS X-specific "Cocoa" APIs to the Java language.
While the first release of the new OS — Mac OS X Server 1.0 — used a modified version of the Mac OS GUI, all versions following used a new GUI known as Aqua. The development of this part of the OS was delayed somewhat by the switch from OpenStep's Display PostScript engine to one that was license free, known as Quartz. Aqua was a fairly radical departure from the Mac OS 9 interface, which was an evolution of the original Macintosh Finder. Aqua incorporated full color scalable graphics, anti-aliasing of text and graphics, simulated shading and highlights, transparency and shadows, and animation. A key new feature was the Dock, an application launcher which took full advantage of these capabilities. Despite this, Mac OS X maintained a substantial degree of compatibility with the traditional Mac OS interface and Apple's own Apple Human Interface Guidelines, with its pull-down menu at the top of the screen, familiar keyboard shortcuts, and support for a single-button mouse.
Releases
Apple released Mac OS X Server 1.0 in January, 1999. A public beta of Mac OS X was released in the year 2000, and March 24, 2001, saw the full and official release of Mac OS X version 10.0. Version 10.1 shipped on September 25, 2001, followed by the August 24, 2002, release of Mac OS X 10.2 "Jaguar"; the October 24, 2003, release of Mac OS X 10.3 "Panther"; and the April 29, 2005, release of Mac OS X 10.4 "Tiger".
- Mac OS X Public Beta
- Mac OS X v10.0 "Cheetah"
- Mac OS X v10.1 "Puma"
- Mac OS X v10.2 "Jaguar"
- Mac OS X v10.3 "Panther"
- Mac OS X v10.4 "Tiger"
- Mac OS X v10.5 "Leopard" (planned for release in late 2006)
Vorlage:Timeline of Macintosh operating systems
See also
External links
- Ars Technica: Mac OS X Q & A
- Ars Technica: Mac OS X GUI
- Ars Technica: Mac OS X DP2 review
- Ars Technica: Mac OS X DP3 review
- Ars Technica: Mac OS X DP4 review
- Ars Technica: Mac OS X Public Beta review
- Ars Technica: Mac OS X 10.0 review
- Ars Technica: Mac OS X 10.1 review
- Ars Technica: Mac OS X 10.2 review
- Ars Technica: Mac OS X 10.3 review
- Ars Technica: Mac OS X 10.4 review
- Mac OS X DP4 review