Editing MacOS (section)

=== PowerPC–Intel transition ===
{{Main|Mac transition to Intel processors}}
[[File:Steve Jobs Presentation 1.jpg|thumb|Steve Jobs talks about the transition to Intel processors.]]
In April 2002, eWeek announced a rumor that Apple had a version of Mac OS X code-named [[Starvin' Marvin in Space|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.<ref>{{Cite web |last1=Rothenbourg |first1=Matthew |last2=dePlume, Nick |date=August 30, 2002 |title=Apple Keeps x86 Torch Lit with 'Marklar' |url=https://www.eweek.com/c/a/Apple/Apple-Keeps-x86-Torch-Lit-with-Marklar |access-date=June 8, 2013 |publisher=eWeek.com |archive-date=September 27, 2022 |archive-url=https://web.archive.org/web/20220927142110/https://www.eweek.com/apple/apple-keeps-x86-torch-lit-with-marklar/ |url-status=live }}</ref> These rumors subsided until late in May 2005, when various media outlets, such as ''[[The Wall Street Journal]]''<ref>{{Cite web |last1=Clark |first1=Don |last2=Wingfield |first2=Nick |date=May 23, 2005 |title=Apple Explores Use Of Chips From Intel For Macintosh Line |url=https://www.wsj.com/articles/SB111680203134440188 |url-status=live |archive-url=https://web.archive.org/web/20150115011437/https://www.wsj.com/articles/SB111680203134440188 |archive-date=January 15, 2015 |access-date=February 8, 2009 |website=[[The Wall Street Journal]] |publisher=[[Dow Jones & Company]] |df=mdy-all}}</ref> and [[CNET]],<ref>{{Cite web |last=Kanellos |first=Michael |date=May 24, 2005 |title=Apple to Intel: Some advantage, lots of risk |url=https://www.cnet.com/news/apple-to-intel-some-advantage-lots-of-risk |access-date=January 22, 2022 |website=[[CNET]] |publisher=[[CBS Interactive]] |archive-date=January 22, 2022 |archive-url=https://web.archive.org/web/20220122014428/https://www.cnet.com/news/apple-to-intel-some-advantage-lots-of-risk/ |url-status=live }}</ref> announced that Apple would unveil Marklar in the coming months.<ref name="I'll See You Intel">{{Cite web |last=Gruber |first=John |author-link=John Gruber |title=I'll See You Intel |url=https://daringfireball.net/2005/06/see_you_intel |url-status=live |archive-url=https://web.archive.org/web/20160313215847/https://daringfireball.net/2005/06/see_you_intel |archive-date=March 13, 2016 |access-date=31 March 2016 |website=Daring Fireball |df=mdy-all}}</ref><ref name="Intel-Apple Odds and Ends">{{Cite web |last=Gruber |first=John |title=Intel-Apple Odds and Ends |url=https://daringfireball.net/2005/06/intel_apple_odds_and_ends |url-status=live |archive-url=https://web.archive.org/web/20050608013302/https://daringfireball.net/2005/06/intel_apple_odds_and_ends |archive-date=June 8, 2005 |access-date=31 March 2016 |website=Daring Fireball |df=mdy-all}}</ref><ref name="Bombs Away">{{Cite web |last=Gruber |first=John |title=Bombs Away |url=https://daringfireball.net/2005/06/bombs_away |url-status=live |archive-url=https://web.archive.org/web/20160411170333/https://daringfireball.net/2005/06/bombs_away |archive-date=April 11, 2016 |access-date=31 March 2016 |website=Daring Fireball |df=mdy-all}}</ref>

On June 6, 2005, Steve Jobs announced in his keynote address at WWDC 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 had versions of Mac OS X running on Intel processors for most of its developmental life. Intel-based Macs would run a new recompiled version of OS X along with [[Rosetta (software)|Rosetta]], a [[binary translation]] layer which enables software compiled for PowerPC Mac OS X to run on Intel Mac OS X machines.<ref name="John Siracusa mourns the Power PC">{{Cite web |last=Siracusa |first=John |date=June 7, 2005 |title=Picking up the pieces: John Siracusa mourns the Power PC |url=https://arstechnica.com/apple/2005/06/mac-20050607 |url-status=live |archive-url=https://web.archive.org/web/20160329184041/https://arstechnica.com/apple/2005/06/mac-20050607 |archive-date=March 29, 2016 |access-date=31 March 2016 |website=[[Ars Technica]] |df=mdy-all}}</ref> The system was included with Mac OS X versions up to version 10.6.8.<ref name="AppleInsider: Mac OS X Lion drops Front Row, Java runtime, Rosetta">{{Cite web |last=AppleInsider Staff |date=February 26, 2011 |title=Mac OS X Lion drops Front Row, Java runtime, Rosetta |url=https://www.appleinsider.com/articles/11/02/26/mac_os_x_lion_drops_front_row_java_runtime_rosetta.html |url-status=live |archive-url=https://web.archive.org/web/20110301003419/https://www.appleinsider.com/articles/11/02/26/mac_os_x_lion_drops_front_row_java_runtime_rosetta.html |archive-date=March 1, 2011 |access-date=February 27, 2011 |website=[[AppleInsider]] |publisher=AppleInsider, Inc}}</ref> Apple dropped support for Classic mode on the new Intel Macs. Third party emulation software such as [[Mini vMac]], [[Basilisk II]] and [[SheepShaver]] provided support for some early versions of Mac OS. A new version of Xcode and the underlying command-line compilers supported building [[universal binary|universal binaries]] that would run on either architecture.<ref>{{Cite press release |title=Apple to Use Intel Microprocessors Beginning in 2006 |date=June 6, 2005 |publisher=[[Apple Inc.|Apple]] |url=https://www.apple.com/newsroom/2005/06/06Apple-to-Use-Intel-Microprocessors-Beginning-in-2006 |access-date=January 2, 2018 |url-status=live |archive-url=https://web.archive.org/web/20180130185804/https://www.apple.com/newsroom/2005/06/06Apple-to-Use-Intel-Microprocessors-Beginning-in-2006 |archive-date=January 30, 2018 |df=mdy-all}}</ref>

PowerPC-only software is supported with Apple's official [[binary translation]] software, [[Rosetta (software)|Rosetta]], though applications eventually had to be rewritten to run properly on the newer versions released for Intel processors. Apple initially encouraged developers to produce universal binaries with support for both PowerPC and Intel.<ref>{{Cite web |date=January 2006 |title=Adopting Universal Binaries |url=https://developer.apple.com/macosx/adoptinguniversalbinaries.html |url-status=live |archive-url=https://web.archive.org/web/20061017075217/https://developer.apple.com/macosx/adoptinguniversalbinaries.html |archive-date=October 17, 2006 |access-date=December 20, 2006 |publisher=[[Apple Inc.|Apple]] |df=mdy-all}}</ref> PowerPC binaries suffer a performance penalty when run on Intel Macs through Rosetta. Moreover, some PowerPC software, such as kernel extensions and System Preferences plugins, are not supported on Intel Macs 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.<ref>{{Cite web |last=Landau |first=Ted |date=May 2006 |title=OS X First Aid |url=https://www.macworld.com/article/50339/2006/04/firstaidintel.html |url-status=live |archive-url=https://web.archive.org/web/20090109080800/https://www.macworld.com/article/50339/2006/04/firstaidintel.html |archive-date=January 9, 2009 |access-date=February 8, 2009 |website=[[Macworld]] |publisher=[[International Data Group|IDG]] |df=mdy-all}}</ref> While Intel Macs can run PowerPC, Intel, and universal binaries, PowerPC Macs support only universal and PowerPC builds.

Support for the PowerPC platform was dropped following the transition. In 2009, Apple announced at WWDC that Mac OS X 10.6 Snow Leopard would drop support for PowerPC processors and be Intel-only.<ref>{{Cite web |last=Stevens |first=Tim |date=June 10, 2009 |title=Snow Leopard officially puts PowerPC Macs on endangered species list |url=https://www.engadget.com/2009/06/10/snow-leopard-officially-puts-powerpc-macs-on-endangered-species |url-status=live |archive-url=https://web.archive.org/web/20100323085015/https://www.engadget.com/2009/06/10/snow-leopard-officially-puts-powerpc-macs-on-endangered-species |archive-date=March 23, 2010 |access-date=June 15, 2009 |website=[[Engadget]] |publisher=[[AOL]] |df=mdy-all}}</ref> Rosetta continued to be offered as an optional download or installation choice in Snow Leopard before it was discontinued with Mac OS X 10.7 Lion.<ref name="MacRumors: Mac OS X Lion: Drops PowerPC Emulation, Adds QuickTime Pro Features, Much More">{{Cite web |last=Arnold Kim |date=February 27, 2011 |title=Mac OS X Lion: Drops PowerPC Emulation, Adds QuickTime Pro Features, Much More |url=https://www.macrumors.com/2011/02/27/mac-os-x-lion-drops-powerpc-emulation-adds-quicktime-pro-features-much-more |url-status=live |archive-url=https://web.archive.org/web/20110227205334/https://www.macrumors.com/2011/02/27/mac-os-x-lion-drops-powerpc-emulation-adds-quicktime-pro-features-much-more |archive-date=February 27, 2011 |access-date=February 27, 2011 |website=[[MacRumors]] |df=mdy-all}}</ref> In addition, new versions of Mac OS X first- and third-party software increasingly required Intel processors, including new versions of iLife, iWork, Aperture and Logic Pro.