Mac OS 9 is the final version of what Apple would call Classic Mac OS and was released prior to the introduction of Mac OS X, now known as macOS. Apple would include what they called "Classic Environment" in Mac OS X from the new operating system's initial release up to 10.4 "Tiger", but that support ended at Mac OS X 10.5 "Leopard", and was never developed to work with Intel-based Macs.
The Classic Environment allowed Mac OS X users to continue to use Mac OS 9 applications inside of the new operating system so they might manage the transition without losing access to applications compatible only with Mac OS 8 & 9. Much of this compatibility was facilitated by Apple's Carbon system extension which allowed developers to quickly adapt their apps to run on both Classic Mac OS and Mac OS X. Carbon would be discontinued on the release of Mac OS X 10.15 "Catalina".
Steve Jobs, at Apple's 2002 World Wide Development Conference a few months after Mac OS 9 was officially discontinued, held a mock funeral for Mac OS 9, but fans of the OS just wouldn't let it die.
Introduced in 1999 as "The Best Internet Operating System Ever", Mac OS 9 would bring a boatload of new internet-oriented features over Mac OS 8, most specifically Sherlock 2, Apple's OS-integrated internet search engine that utilized "Channels" to narrow down searches from plug-in based sources both local and internet-based, such as the internet, Pictures, Stocks, Flights, and eBay. Additional channels would be added over Mac OS 9's two-year lifespan. Promotional material for Mac OS 9 would state that the new OS was "You Internet Co-pilot" long before Microsoft would call their AI assistant the same.
Some of the major new features added to Mac OS 9, aside from Sherlock 2, were the following:For additional details on the operating system itself and which Mac OS 9 versions can natively run on which Power Macintosh systems, click here. [SOURCE: Wikipedia]
- Integrated support for iTools, Apple's suite of internet-enabled applications and services (later known as .Mac, MobileMe, and now iCloud).
- Improvements to internet access with OpenTransport 2.5.
- Multiple user support.
- Voice login using VoicePrint passwords.
- The first version of Apple's Keychain for storing and using passwords.
- Automatic internet software updates.
- Support for USB audio devices.
- PlainTalk's Speakable Items 2.0, a speech synthesis and voice command recognition system, with support for AppleScript.
- Support for TCP/IP in an updated version of AppleScript.
- Personal file sharing over TCP/IP.
- USB printer sharing and access over TCP/IP for specific printer models.
- File encryption in the Finder.
- Support for files larger than 2GBs in size.
- Support for UNIX volume support.
- Support for burning CDs in the Finder.
Despite Apple blocking support for natively booting on most Apple Macs with PowerPC G4 processors, there has been some work done by the community to make some of them work. Some of these systems are:The original version of this list is from this Mac OS 9 Wikipedia entry.
- Mac Mini G4
- PowerBook G4 (5,1 - 5,4)
- eMac G4
- PowerMac G4 MDD
- iMac G4
