Re: Newest Version Of Mac Os X Snow Leopard
Florene Franca
Mac OS X Snow Leopard (version 10.6) (also referred to as OS X Snow Leopard[10]) is the seventh major release of macOS, Apple's desktop and server operating system for Macintosh computers.
The goals of Snow Leopard were improved performance, greater efficiency and the reduction of its overall memory footprint, unlike previous versions of Mac OS X which focused more on new features. Apple famously marketed Snow Leopard as having "zero new features".[12] Its name signified its goal to be a refinement of the previous OS X version, Leopard.[13] Much of the software in Mac OS X was extensively rewritten for this release in order to take full advantage of modern Macintosh hardware and software technologies (64-bit, Cocoa, etc.). New programming frameworks, such as OpenCL, were created, allowing software developers to use graphics cards in their applications. It was also the first Mac OS release since System 7.1.1 to not support Macs using PowerPC processors, as Apple dropped support for them and focused on Intel-based products.[2] As support for Rosetta was dropped in Mac OS X Lion, Snow Leopard is the last version of Mac OS X that is able to run PowerPC-only applications.
Snow Leopard was succeeded by OS X Lion (version 10.7) on July 20, 2011.[14] For several years, Apple continued to sell Snow Leopard at its online store for the benefit of users that required Snow Leopard in order to upgrade to later versions of OS X. Snow Leopard was the last version of Mac OS X to be distributed primarily through optical disc, as all further releases were mainly distributed through the Mac App Store introduced in the Snow Leopard 10.6.6 update.[15]
Snow Leopard is the last version of Mac OS X that supports the 32-bit Intel Core Solo and Intel Core Duo CPUs. Because of this, Snow Leopard still remained somewhat popular alongside OS X Lion, despite its lack of continued support,[16] mostly because of its ability to run PowerPC-based applications.[citation needed]
Snow Leopard drops support for PowerPC-based Macs (e.g., Power Macs, PowerBooks, iBooks, iMacs (G4 and G5), all eMacs, plus pre-February 2006 Mac Minis and the Power Mac G4 Cube), although PowerPC applications are supported via Rosetta, which is now an optional install. In 2020, two developer previews of Snow Leopard that are universal appeared on the Internet that can be booted on select G4 and G5 Power Macs with modification and patching.[19]
Snow Leopard is available as an upgrade for Intel-based Macintosh computers. Single-user licenses and "family pack" licenses for up to five computers are available. For qualifying Mac computers bought after June 8, 2009, Apple offered a discounted price through its "up-to-date" program, provided that customers' orders were faxed or postmarked by December 26, 2009. The standalone retail version of Snow Leopard is marketed as being restricted to users of Mac OS X Leopard, while the recommended upgrade path from Apple for Mac OS X Tiger is through the "Mac Box Set", which includes Mac OS X Snow Leopard and the current versions of iLife and iWork.
If you have purchased an Upgrade for Mac OS X Leopard license, then subject to the terms and conditions of this License, you are granted a limited non-exclusive license to install, use and run one (1) copy of the Apple Software on a single Apple-branded computer as long as that computer has a properly licensed copy of Mac OS X Leopard already installed on it.[21]
Subject to the terms and conditions of this License ... you are granted a limited non-exclusive license to install, use and run one (1) copy of the Apple Software on a single Apple-branded computer at a time.[21]
It is not entirely clear which license is offered with the retail version of Snow Leopard. As noted above, Apple's website advertised this version as an "upgrade from Mac OS X Leopard for $29" and suggest that others upgrade using the Mac Box Set, implying the stand-alone retail version to be a "Leopard Upgrade" license. On the other hand, some Apple press materials appear to indicate that this version is, in fact, the "Single Use" license:
However, even if the retail edition of Snow Leopard is in fact a "Leopard Upgrade", the company has acknowledged that there is no technical barrier in that edition preventing a direct upgrade from Mac OS X "Tiger".[23]
The Leopard Upgrade license explicitly applies to the Up-To-Date Program[24] (US$9.95) for Macs bought between June 8 and December 26, 2009[25] and the installation discs provided through this program are clearly marked as upgrades unlike either of the retail editions.
Mac OS X Snow Leopard is a release that refined the existing feature set, expanded the technological capabilities of the operating system, and improved application efficiency.[neutrality is disputed] Many of the changes involve how the system works in the background and are not intended to be seen by the user. For example, the Finder application was completely rewritten in the Cocoa application programming interface, from its previous Carbon codebase.[26] Despite significant changes in the software, users will experience almost no changes in the user interface. Snow Leopard includes the following changes:
While the Finder was completely rewritten in Cocoa, it did not receive a major user interface overhaul. Instead, the interface has been modified in several areas to promote ease of use. These changes include:
As with most upgrades of Mac OS X, new wallpapers are available. There are new wallpapers in the Nature (two of which are of snow leopards), Plants and Black and White sub-folders under the Apple folder. Furthermore, there are new Apple wallpaper sub-folders with multiple wallpapers:
New solid colors can be used as wallpapers as well. There is a new blue and gray, as well as a solid kelp which serves as the "green wallpaper." The default "space nebula" wallpaper has been updated as well.
Mac OS X Tiger added limited support for 64-bit applications on machines with 64-bit processors; Leopard extended the support for 64-bit applications to include applications using most of Mac OS X's libraries and frameworks.
In Snow Leopard, most built-in applications have been rebuilt to use the 64-bit x86-64 architecture (excluding iTunes, Front Row, Grapher and DVD Player applications).[42] They will run in 32-bit mode on machines with 32-bit processors, and in 64-bit mode on machines with 64-bit processors.
In addition, the Mac OS X kernel has been rebuilt to run in 64-bit mode on some machines. On those machines, Snow Leopard supports up to 16 terabytes of RAM. Newer Xserve and Mac Pro machines will run a 64-bit kernel by default; newer iMac and MacBook Pro machines can run a 64-bit kernel, but will not do so by default.[43] Users wishing to use the 64-bit kernel on those machines must hold down the numbers 6 and 4 on the keyboard while booting to get the 64-bit kernel to load.[44][45] A change to the com.apple.Boot.plist will also enable users with compatible computers to permanently boot into 64-bit for those wishing to do so.
Stuart Harris, software product marketing manager at Apple Australia, said, "For the most part, everything that they experience on the Mac, from the 64-bit point of view, the applications, the operating system, is all going to be 64-bit, but that at this stage there were very few things, such as device drivers, that required 64-bit mode at the kernel level".[45]
.mw-parser-output .citationword-wrap:break-word.mw-parser-output .citation:targetbackground-color:rgba(0,127,255,0.133)^* Amit Singh has reported that the early 2009 Mac Mini and MacBook may be capable of running the 64-bit kernel; however, Apple has set these models to boot into the 32-bit kernel. With some tweaking, the Unibody MacBook can be set to boot the 64-bit kernel.[48]
Grand Central Dispatch (GCD) uses the multiple processor cores now in every new Macintosh for more efficient performance. Due to the complexity of multithreaded programming and technical difficulties traditionally involved in making applications optimized for multicore CPUs, the majority of computer applications do not effectively use multiple processor cores.[49] As a result, additional processing power, compared to single-core machines, often goes unused. Grand Central Dispatch includes APIs to help programmers efficiently use these cores for parallel programming.
OpenCL (Open Computing Language) addresses the power of graphics processing units (GPUs) to leverage them in any application, and not just for graphics-intensive applications like 3D games. OpenCL automatically optimizes for the kind of graphics processor in the Mac, adjusting itself to the available processing power. OpenCL provides consistent numeric precision and accuracy, fixing a problem that has hampered GPU-based programming in the past.[54]
OpenCL includes a C-based programming language with a structure that is already familiar to Mac OS X programmers, who can use Xcode developer tools to adapt their programs to work with OpenCL. Only the most process intensive parts of the application need to be written in OpenCL C without affecting the rest of the code. OpenCL is an open standard that has been supported by AMD, Intel, and Nvidia; it is maintained by Khronos Group.[30]
CUPS (the printing system used in many Unix-like operating systems) has been updated to version 1.4 which provides improved driver, networking, and Kerberos support along with performance improvements. CUPS 1.4 is also the first implementation of the Internet Printing Protocol version 2.1.[56]
Power management has been improved, with implementation of a new wake on demand feature supported on more recent Macintosh hardware.[57] Wake on demand takes advantage of the sleep proxy service implemented in AirPort and Time Capsule routers,[58] so that the computer can sleep while the router responds to mDNS queries. Should the request require the host computer to wake up, the router sends the necessary special wake-up-packet[59] to the sleeping computer.
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