"You are holding the future of the Macintosh in your hands." The year 2000 marked Mac OS X's first, public appearance in the form of a Public Beta. For $29.95, you get an unfinished, buggy version of Apple's next generation operating system, in a folder (not a box), with the above greeting in its inside flap.
Fast forward to 2005, and we have since enriched our vocabulary with "ordinary" words as Graphite, Aqua, Quartz, Dock, Exposé, Rendezvous (which is now all Frenchy Bonjour), Dashboard, Spotlight, etc. Even Unix terms such as Kernel and Terminal have found their way into the average Mac user's command line-phobic vocabulary.
Most significantly, Mac OS X's Unix heritage have proven that Unix can be all of stable, secure, user-friendly and beautiful. A concept hardly in the minds of most Unix users in the past. The most significant Unix interface innovation that I can recall is virtual desktops. Showing off Exposé or Dashboard to a Unix user a decade ago and telling him it runs on Unix would probably blow his mind.
2005 heralded the Chinese Year of the Rooster. But as far as Mac users go, it's the Year of the Tiger. We've gone through Cheetah, Puma, Jaguar (Jagwire), and Panther, and along the way, Mac OS X has given us iTunes, iPhoto, iMovie, iChat, iCal, iDVD, and all the other iApps as part of iLife or the recent iWork apps. We've never had this much fun in OS 9, but of course the times were different, and Mac OS X has kept us up with the times.
Mac OS X, encompassing all its feline lineage: past, Friday the 29th, and future, clearly is Apple's most significant OS, and whets our appetite for more Apple innovations to come.
The Great Tiger Giveaway