Unlike Leopard, Mac OS X Snow Leopard did not include hundreds of new features. Instead, the update was primarily designed to improve the performance and efficiency of Mac OS X. Snow Leopard was the first Mac operating system to require an Intel-based Mac, which means it cannot be used on older Macintosh computers. However, by removing the PowerPC code from the operating system, Apple was able to shrink the size of the operating system by roughly 7 gigabytes compared to Leopard and improve the speed of common operations.
While Snow Leopard was not a feature-oriented release, it did include a few notable additions. For example, Snow Leopard was the first version of Mac OS X to include autocorrect support, which automatically fixes common typos. Additionally, Snow Leopard added Microsoft Exchange support to Mail, Address Book, and iCal, which is important for Macs that are used in Windows-based organizations. Mac OS 10.6 also shipped with several new versions of Apple software, including Safari 4, iChat 5, and QuickTime X, a completely rewritten version of QuickTime.
The final Snow Leopard software update was 10.6.8, released on July 25, 2011.
Updated: October 24, 2012