Mac OS X Snow Leopard

Mac OS X Snow Leopard, or Mac OS X 10.6, is an operating system developed by Apple and the seventh major release of Mac OS X. Snow Leopard is one of Apple's longest lasting Mac OS X operating systems with five years of support and launched with largely positive reviews.

Differences from Leopard

 * Removed support for the PowerPC architecture due to Apple's intent to support Intel processors.
 * It is also the last version to have Rosetta, and thus the last version to run PowerPC-only applications.
 * Finder has been rewritten in Cocoa to take the advantages of Mac OS X. Before that, Finder was based on the Carbon API.
 * On 64-bit systems, the kernel now also runs in 64-bit.
 * Version 10.6.6 introduced the Mac App Store, an ESD marketplace for free and paid programs for macOS.