In June 2005, Jobs announced that the Macintosh platform would be transitioning to Intel x86 microprocessors. Mac OS 9.2.2, released in December 2001, was the final version of Mac OS 9 and the 'classic' Mac OS. In May 2002, at Apple's Worldwide Developers Conference in San Jose, California, Steve Jobs, accompanied by a coffin, held a mock funeral to announce that Apple had stopped development of Mac OS 9.

In addition, some drivers and other software which directly interact with the hardware fail to work properly. They demonstrate screen redraw problems and lagging performance. Some Mac OS 9 applications do not run well in Classic. This requires Mac OS 9 to be installed on the computer even though computers that can run the Classic environment are not necessarily able to boot into Mac OS 9.

This is achieved through running Mac OS 9 without access to its Finder inside OS X. PowerPC versions of Mac OS X prior to 10.5 include a compatibility layer (a shell) called Classic, enabling users to run applications and hardware requiring Mac OS 9 from within OS X. Addition of a 'Window' menu to the Finder (introduced in Mac OS 9.1).CD Burning in the Finder (introduced in Mac OS 9.1).USB Printer Sharing, a control panel allowing certain USB printers to be shared across a TCP/IP network.An updated version of AppleScript with support for TCP/IP.Remote Access Personal Server 3.5, including support for TCP/IP clients over Point-to-Point Protocol (PPP).Improved font management through FontSync.Speakable Items 2.0, also known as PlainTalk, featuring improved speech synthesis and recognition along with AppleScript integration.A redesigned Sound control panel and support for USB audio.A Software Update control panel for automatic download and installation of Apple system software updates.Keychain, a feature allowing users to save passwords and textual data encrypted in protected keychains.Support for voice login through VoicePrint passwords.

Integrated support for multiple user accounts without using At Ease.Mac, then MobileMe, which was replaced by iCloud) and included improved TCP/IP functionality with Open Transport 2.5. Mac OS 9 also featured integrated support for Apple's suite of Internet services known as iTools (later re-branded as. Apple billed Mac OS 9 as including '50 new features' and heavily marketed its Sherlock 2 software, which introduced a 'channels' feature for searching different online resources and introduced a QuickTime-like metallic appearance.

Mac os 9.2.2 to mac os x 10.0