Friday, January 13, 2012

Mac OS X - Business

history br main article history of x br x is based upon the mach kernel certain parts from freebsd s and netbsd s implementation of unix were incorporated in nextstep the core of x nextstep was the object oriented operating system developed by steve jobs company next after he left apple in 1985 while jobs was away from apple apple tried to create a next generation os through the taligent copland and gershwin projects with little success br eventually next s os then called openstep was selected to be the basis for apple s next os and apple purchased next outright steve jobs returned to apple as interim ceo and later became ceo shepherding the transformation of the programmer friendly openstep into a system that would be adopted by apple s primary market of home users and creative professionals the project was first known as rhapsody and was later renamed to x br x server 1 x was incompatible with software designed for the original and had no support for apple s own ieee 139 4 interface firewire x 10 x included more backward compatibility and functionality by including the carbon api as well as firewire support as the operating system evolved it moved away from the legacy to an emphasis on new digital lifestyle applications such as the ilife suite enhanced business applications iwork and integrated home entertainment the front row media center each version also included modifications to the general interface such as the brushed metal appearance added in version 10 3 the non pinstriped titlebar appearance in version 10 4 and in 10 5 the removal of the previous brushed metal styles in favor of the unified gradient window style br description br box artwork for x left to right cheetah puma 1 jaguar 2 panther 3 tiger 4 leopard 5 and snow leopard 6 br x is the tenth major version of apple s operating system for macintosh computers previous macintosh operating systems were named using arabic numerals e g 8 and 9 the letter x in x s name refers to the number 10 a roman numeral it is therefore correctly pronounced ten tn in this context though x ks is also a common pronunciation br x s core is a posix compliant operating system os built on top of the xnu kernel with standard unix facilities available from the command line interface apple released this family of software as a free and open source operating system named darwin but it later became partially proprietary on top of darwin apple layered a number of components including the aqua interface and the finder to complete the gui based operating system which is x br x introduced a number of new capabilities to provide a more stable and reliable platform than its predecessor 9 for example pre emptive multitasking and memory protection improved the system s ability to run multiple applications simultaneously without them interrupting or corrupting each other many aspects of x s architecture are derived from openstep which was designed to be portable to ease the transition from one platform to another for example nextstep was ported from the original 68k based next workstations to x86 and other architectures before next was purchased by apple and openstep was later ported to the powerpc architecture as part of the rhapsody project br the most visible change was the aqua theme the use of soft edges translucent colors and pinstripes similar to the hardware design of the first imacs brought more texture and color to the user interface when compared to what os 9 and os x server 1 0 s platinum appearance had offered according to john siracusa an editor of ars technica the introduction of aqua and its departure from the then conventional look hit like a ton of bricks however bruce tognazzini who founded the original apple human interface group said that the aqua interface in x v10 0 represented a step backwards in usability compared with the original interface despite the controversial new interface third party developers started producing skins for customizable applications for mac and other operating systems which mimicked the aqua appearance to some extent apple has used the successful transition to this new design as leverage at various times threatening legal action against people who make or distribute software with an interface the company claims is derived from its copyrighted design br x architecture implements a layered framework the layered framework aids rapid development of applications by providing existing code for common tasks br x includes its own software development tools most prominently an integrated development environment called xcode xcode provides interfaces to compilers that support several programming languages including c c objective c and java for the applentel transition it was modified so that developers could build their applications as a universal binary which provides compatibility with both the intel based and powerpc based macintosh lines br the darwin sub system in x is in charge of managing the filesystem which includes the unix permissions layer in 2003 and 2005 two macworld editors expressed criticism of the permission scheme ted landau called misconfigured permissions the most common frustration in x while rob griffiths suggested that some users may even have to reset permissions every day a process which can take up to 15 minutes more recently another macworld editor dan frakes called the procedure of repairing permissions vastly overused he argues that x typically handles permissions properly without user interference and resetting permissions should be tried only when problems emerge br as of 2009 x is the second most popular general purpose operating system in use for the internet after microsoft windows with a 4 5 market share according to statistics compiled by net applications in contrast it is the most successful unix like desktop operating system on the internet estimated at over 4 times the penetration of the free linux x is available in a variety of languages including english japanese french german spanish portuguese and italian br compatibility br software br the apis that x inherited from openstep are not backward compatible with earlier versions of these apis were created as the result of a 1993 collaboration between next computer and sun microsystems and are now referred to by apple as cocoa this heritage is highly visible for cocoa developers since the ns prefix is ubiquitous in the framework standing variously for nextstep or next sun the official openstep api published in september 1994 was the first to split the api between foundation and application kit and the first to use the ns prefix apple s rhapsody project would have required all new development to use these apis causing much outcry among existing mac developers all mac software that did not receive a complete rewrite to the new framework would run in the equivalent of the classic environment to permit a smooth transition from 9 to x the car bon application programming interface api was created applications written with carbon can be executed natively on both systems carbon was not included in the first product sold as mac os x mac os x server now known as mac os x server 1 x br mac os x used to support the java platform as a preferred software package in practice this means that applications written in java fit as neatly into the operating system as possible while still being cross platform compatible and that graphical user interfaces written in swing look almost exactly like native cocoa interfaces traditionally cocoa programs have been mostly written in objective c with java as an alternative however on july 11 2005 apple announced that features added to cocoa in mac os x versions later than 10 4 will not be added to the cocoa java programming interface br since mac os x is posix compliant many software packages written for the bsds or linux can be recompiled to run on it projects such as fink macports and p kgsrc provide pre compiled or pre formatted packages since version 10 3 mac os x has included x11 app apple s version of the x window system graphical interface for unix applications as an optional component during installation up to and including mac os x v10 4 tiger apple s implementation was based on the x11 licensed xfree86 4 3 and x11r6 6 all bundled versions of x11 feature a window manager which is similar to the mac os x look and feel and has fairly good integration with mac os x also using the native quartz rendering system earlier versions of mac os x in which x11 has not been bundled can also run x11 applications using xdarwin with the introduction of version 10 5 apple switched to the x org variant of x11 br hardware br for the early releases of mac os x the standard hardware platform supported was the full line of macintosh computers laptop desktop or server based on powerpc g3 g4 and g5 processors later versions discontinued support for some older hardware for e xample panther does not support beige g3s and tiger does not support systems that pre date apple s introduction of integrated firewire ports however the ports themselves are not a functional requirement mac os x v10 5 leopard introduced october 2007 has dropped support for all powerpc g3 processors and for powerpc g4 processors with clock rates below 867 160 mhz mac os x v10 6 snow leopard supports only macs with intel processors not powerpc br tools such as xpostfacto and patches applied to the installation disc have been developed by third parties to enable installation of newer versions of mac os x on systems not officially supported by apple this includes a number of pre g3 power macintosh systems that can be made to run up to and including mac os x 10 2 jaguar all g3 based macs which can run up to and including tiger and sub 867 160 mhz g4 macs can run leopard by removing the restriction from the installation dvd or entering a command in the mac s open firmware interfac e to tell the leopard installer that it has a clock rate of 867 160 mhz or greater except for features requiring specific hardware e g graphics acceleration dvd writing the operating system offers the same functionality on all supported hardware br powerpc versions of mac os x prior to leopard retain compatibility with older mac os applications by providing an emulation environment called classic which allows users to run mac os 9 as a process within mac os x so that most older applications run as they would under the older operating system classic is not supported on intel based macs or in mac os x v10 5 leopard although users still requiring classic applications on intel macs can use the sheepshaver emulator to run mac os 9 on top of leopard br applentel transition br main article applentel transition br in april 2002 eweek reported a rumor that apple had a version of mac os x code named marklar which ran on intel x86 processors the idea behind marklar was to keep mac os x running on an alternative platform should apple become dissatisfied with the progress of the powerpc platform these rumors subsided until late in may 2005 when various media outlets such as the wall street journal and cnet reported that apple would unveil marklar in the coming months br on june 6 2005 steve jobs confirmed these rumors when he announced in his keynote address at the annual apple worldwide developers conference that apple would be making the transition from powerpc to intel processors over the following two years and that mac os x would support both platforms during the transition jobs also confirmed rumors that apple has had versions of mac os x running on intel processors for most of its developmental life the last time that apple switched cpu familiesrom the motorola 68k cpu to the ibm motorola powerpcpple included a motorola 68k emulator in the new os that made almost all 68k software work automatically on the new hardware apple had supported the 68k emul ator for 11 years but stopped supporting it during the transition to intel cpus included in the new os for the intel based macs is rosetta a binary translation layer which enables software compiled for powerpc mac os x to run on intel mac os x machines however apple dropped support for classic mode on the new intel macs third party emulation software such as mini vmac basilisk ii and sheepshaver provides support for some early versions of mac os a new version of xcode and the underlying command line compilers support building universal binaries that will run on either architecture br software that is available only for powerpc is supported with rosetta though applications may have to be rewritten to run properly on the newer os x for intel apple encourages developers to produce universal binaries with support for both powerpc and x86 there is a performance penalty when powerpc binaries run on intel macs through rosetta moreover some powerpc software such as kernel extensions and system preferences plugins are not supported on intel macs some powerpc applications would not run on intel os x at all plugins for safari need to be compiled for the same platform as safari so when safari is running on intel it requires plug ins that have been compiled as intel only or universal binaries so powerpc only plug ins will not work while intel macs will be able to run powerpc x86 and universal binaries powerpc macs will support only universal and powerpc builds br support for the powerpc platform remains in mac os x version 10 5 such cross platform capability already existed in mac os x s lineage openstep was ported to many architectures including x86 and darwin included support for both powerpc and x86 although apple stated that mac os x would not run on intel based personal computers aside from its own a hacked


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