I just did a quick search through my blog to see if I had posted on the argument that new versions of Mac OS X are just Service Packs, rather than full upgrades. I have mentioned it in one where I went through Paul Thurrott's review of Leopard but never had I set in stone the cold hard facts.

Jaguar, Panther, Tiger, Leopard, they aren't Service Packs. The only Service Pack-like release Apple have ever made was Mac OS X 10.1, Puma. Puma was free. If you had Cheetah, you got Puma for free. You could by Puma but only if you didn't have Cheetah. It was a Service Pack in every sense. Only core enhancements such as:

• Performance enhancements
  
• Easier CD and DVD burning
  
• DVD playback support
  
• More printer support
  
• Faster 3D
  
• Improved AppleScript
  
• ColorSync 4.0
  
• Image Capture

When compared to, say, Service Pack 1 for Windows XP you can clearly see the resemblance.

• Post-RTM security fixes and hot-fixes
  
• Compatibility updates
  
• Optional .NET Framework support
  
• Enabling technologies for new devices such as Tablet PCs
  
• Windows Messenger 4.7
  
• USB 2.0 support
  
• Set Program Access and Defaults utility

They both offer compatibility and technology upgrades, and cost nothing.

Well technically that wasn't very fair. Windows XP Service Pack 1 came out only one month after Mac OS X 10.2, Jaguar. But Jaguar cost money. What did it offer that Puma and Service Pack 1 didn't?

• Address Book
  
• Rendezvous
  
• CUPS
  
• A revamped Finder with searching built directly into every window
  
• An adaptive spam mail filter
  
• Network support for Microsoft Windows networks
  
• Quartz Extreme
  
• Sherlock 3
  
• Universal Access
  
• Increased speed
  
• Journaled file system
  
• iChat
  
• Inkwell
  
• Darwin 6.0.1/6.0.2

That last one is the most important reason it cost money. Mac OS X 10.2 was using the next version of Darwin under the hood. Darwin is the underlying system underneath Mac OS X, based on OPENSTEP, the open source continuation of NEXTSTEP.

Continuing on, let's look at Mac OS X 10.3, Windows XP Service Pack 2, and Mac OS 10.4.

Mac OS X 10.3, Panther:

• Updated Finder with a brushed-metal interface, a new real-time search engine, customizable Sidebar, secure deletion, File labels and Zip support
  
• Fast User Switching
  
• Exposé
  
• TextEdit is now compatible with Microsoft Word documents
  
• gcc 3.3
  
• Increased speed with PDF rendering in Preview
  
• QuickTime now supports the Pixlet high definition video codec
  
• CoreAudio
  
• Font Book
  
• FileVault
  
• iChat AV
  
• X11
  
• Microsoft Windows interoperability improvements
  
• Fax support
  
• Darwin 7.0

Windows XP, Service Pack 2:

• Improved Wi-Fi support
  
• A pop-up ad blocker for Internet Explorer
  
• Bluetooth support
  
• Major revision of the included firewall
  
• Advanced memory protection
  
• Removal of raw socket support
  
• Security-related improvements to e-mail and web browsing
  
• Windows Security Center

Mac OS X 10.4, Tiger:

• Spotlight
  
• iChat AV 3
  
• Safari 2.0
  
• Mail 2
  
• Dashboard
  
• Automator
  
• VoiceOver
  
• A complete Dictionary/Thesaurus
  
• .Mac syncing improvements
  
• QuickTime 7
  
• New Unix features
  
• Xcode 2.0
  
• Grapher
  
• Quartz Composer
  
• AU Lab
  
• launchd
  
• Print to PDF
  
• Core Image
  
• Core Data
  
• Core Video
  
• Darwin 8.0
  
• Many more improvements

Well I think it's plainly obvious that Tiger is, at least, not a Service Pack. And again, they both featured upgrades to the next major version of Darwin. But hey, want one last kick in the the sweet spot? Check out Leopard's upgrades. I'm not going to list them, I'm not crazy. It's based on Darwin 9.0 by the way...

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