Tiger
This ferocious cat is the code name for Mac OS X 10.4, released April 29, 2005. Tiger follows a list of other felines in the Mac OS X lineup, including Panther (10.3), Jaguar (10.2), Puma (10.1), and Cheetah (10.0). Apple originally used the cat names as internal names for the operating system development, but actually started to market the names with the release of Jaguar.
According to Apple, Tiger includes over 200 improvements from Mac OS X 10.3. A few of the most notable additions include an enhanced search feature called "Spotlight," an internal scripting program called "Automator," and quick information access via widgets from the new "Dashboard." Mac OS X 10.4 Tiger is a feature-rich operating system that some may consider as a serious alternative to Windows.