Mac OS applications could be rewritten to run natively via the Carbon API; many could also be run directly through the Classic Environment with a reduction in performance.The consumer version of Mac OS X was launched in 2001 with Mac OS X 10.0.In 2011, Apple released Mac OS X 10.7 Lion, which no longer supported 32-bit Intel processors and also did not include Rosetta.All versions of the system released since then run exclusively on 64-bit Intel CPUs and do not support Power PC applications.Previous Macintosh operating systems (versions of the classic Mac OS) were named using Arabic numerals, as with Mac OS 8 and Mac OS 9.
Ars Technica columnist John Siracusa, who reviewed every major OS X release up to 10.10, described the early releases in retrospect as 'dog-slow, feature poor' and Aqua as 'unbearably slow and a huge resource hog'.
Version 10.4, Tiger, reportedly shocked executives at Microsoft by offering a number of features, such as fast file searching and improved graphics processing, that Microsoft had spent several years struggling to add to Windows with acceptable performance.
Targeting the consumer and media markets, Apple emphasized its new "digital lifestyle" applications such as the i Life suite, integrated home entertainment through the Front Row media center and the Safari web browser.
Mac OS X 10.5 Leopard was released as a Universal binary, meaning the installer disc supported both Intel and Power PC processors.
Mac OS X 10.6 Snow Leopard was the first release to be available exclusively for Intel-based Macs.