Remember Cheetah? Or Puma? Or Snow Leopard? If you are a Mac user, you likely have fond memories of these different versions of OS X. If you want to take a walk down memory lane, then you should check out iMore, which has an interesting piece on OS X and its evolution to Mavericks.
iMore starts with the radical jump from Mac OS 9 to OS X, when Apple adopted a UNIX foundation for its desktop OS. The company originally released new versions of OS X on a yearly basis, until it hit OS X 10.3 Panther. At this point, Apple moved to a biannual upgrade cycle.
Somewhere in the middle of these desktop upgrades, Apple switched from its PowerPC architecture to Intel-based hardware. It was smooth sailing as the company made this transition during those Tiger, Leopard and Snow Leopard years.
When Mountain Lion debuted in 2012, Apple recommitted itself to a yearly upgrade cycle and used its last cat breed for the name of its desktop OS. Now we have OS X 10.9 Mavericks, a name taken from a popular California surfing location. Apple added a lot in this latest version of OS X, improving memory and battery performance as well as bringing OS X and iOS closer together via iCloud.
You can read more about the path to OS X Mavericks in the iMore article.