Mac OS 9

Mac OS 9
Version of the classic Mac OS operating system
Screenshot of Mac OS 9.2.2
DeveloperApple Computer
OS familyMacintosh
Working stateHistoric, unsupported
Source modelClosed source
Released to
manufacturing
October 23, 1999 (October 23, 1999)
Latest release9.2.2 / December 5, 2001 (2001-12-05)
Supported platformsPowerPC
Kernel typeMicrokernel
Default
user interface
Apple Platinum
LicenseProprietary
Preceded byMac OS 8
Succeeded by
Official websiteApple - Products - Mac OS 9 at the Wayback Machine (archived November 9, 2000)
TaglineYour Internet co-pilot.
Support status
Historical, unsupported as of February 1, 2002

Mac OS 9 is the ninth and final major release of the classic Mac OS operating system for Macintosh computers, developed by Apple. Released on October 23, 1999, it was promoted by Apple as "The Best Internet Operating System Ever", reflecting new Internet features including the Sherlock 2 search tool, integration with the company's iTools online services, and improvements to Open Transport networking.

Mac OS 9 introduced features including an automated Software Update function and multi-user support, but retained the cooperative multitasking and memory architecture of earlier versions of the classic Mac OS, lacking protected memory and full pre-emptive multitasking. It was succeeded by Mac OS X 10.0 in 2001, the first release of the Mac OS X operating system family.

Apple ended development of Mac OS 9 in late 2001 as it transitioned to Mac OS X. The final Mac OS 9 updates focused on compatibility with the Classic Environment and Carbon applications. At the 2002 Worldwide Developers Conference, Steve Jobs opened his keynote with a mock funeral for Mac OS 9, symbolizing Apple's transition to Mac OS X.