Mac OS X

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Revision as of 10:53, 2 March 2007 by imported>Alex Bravo (→‎Description)
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A screenshot of the developer preview of Mac OS 10.5 "Leopard".

Mac OS X is a proprietary, Unix-like operating system developed, marketed, and sold by Apple Inc., which currently ships on all Macintosh computers. It succeeds the original Mac OS with its Aqua graphical user interface and Cocoa API, based on technologies of the dead OPENSTEP operating system from NeXT, absorbed with Apple's purchase in late 1996.[1] The operating system was first released in 1999 in the form Mac OS X Server 1.0, with a desktop-oriented version following in March 2001. Mac OS X has ever since become the most used and probably most popular Unix in the world. Its open source core, named Darwin, is based on FreeBSD and the Mach microkernel and integrates many open source software.[2] It comes with Apple's free software development suite named Xcode. Freely supplied with every Macintosh.

History

Following the limited success of Apple attempts to modernize its Mac OS (the Copland Project), the company decided to use existing technology for the tenth version of its operating system. While Be Inc seemed to be the most appropriate candidate, NeXT's technologies were chosen as the basis for Apple's new operating system. Rhapsody, code name for the system, joined the Mach microkernel, a BSD operating system layer, the Yellow Box object-oriented frameworks from OPENSTEP and the Blue Box environment for backwards-compatibility with the classic Mac OS. Rhapsody evolved into Mac OS X Server 1.0[3], which became the predecessor to Mac OS X. Each new version of Mac OS X evolved away from its backward compatibility with the earlier versions of Mac OS, with the transition to Intel processors making Apple finally discard the Classic mode, included in versions for the PowerPC.

Mac OS X has seen 5 releases as of early 2007. Mac OS 10.0 was the first release, and Mac OS 10.4 is the most recent, with a projected release of the next major iteration —Mac OS 10.5 "Leopard"— sometime in spring 2007.

Description

Mac OS X is a radical departure from previous Macintosh operating systems, its underlying code base being completely different from previous versions. Unlike its predecessors, Mac OS X is a Unix-like operating system and includes standard Unix utilities, available from the command line interface. Darwin, the core of the operating system, is built on top of the hybrid kernel XNU, which is a combination of the Mach 3 microkernel, various elements of FreeBSD 5 like the process model, network stack, and virtual file system and an object-oriented device driver API called I/O Kit. Apple layered over Darwin a number of proprietary components, most notably the Quartz graphics layer and the Aqua interface, to complete the GUI-based operating system which is Mac OS X.

Mac OS X includes a number of features intended to make the operating system more stable and reliable than Apple's previous operating systems. Pre-emptive multitasking and memory protection, for example, improved the ability of the operating system to run multiple applications simultaneously without them interrupting or corrupting each other. Many aspects of Mac OS X's architecture are derived from OPENSTEP, which was designed with portability in mind, thus easing the transition from one platform to another. NEXTSTEP was ported from the original 68k-based NeXT workstations to other architectures before NeXT was purchased by Apple, and OPENSTEP was subsequently ported to the PowerPC architecture as part of the Rhapsody project. Thus, Mac OS X is able to run on multiple platforms, with builds in Apple products running on PowerPC processors, x86 and x86-64 processors, and at least one form of ARM processor.

Versions

Version Code name* Release date Major new features
10.0 Cheetah March 24, 2001[4]
10.1 Puma September 25, 2001 CD and DVD burning, DVD Player[5]
10.2 Jaguar August 24, 2002 iChat[6]
10.3 Panther October 24, 2003 Exposé, Safari[7]
10.4 Tiger April 29, 2005 Spotlight, Dashboard[8]
10.5 Leopard Spring 2007 Time Machine, ZFS, Spaces[9]
  • From version 10.2 onwards, code names were employed for branding.

References

External links