It underwent its largest revision to date with the introduction of the aqua interface in 2005s mac OS x. It was a new operating system built primarily on technology from next step with UI elements of the original Mac OS grafted on. Mac OS X uses a technology known as graphic layer, for graphics rendering and drawing on-screen. Some interface features of Mac OS X are inherited from NeXTStep (such as the dockthe automatic wait cursor, or double-buffered windows giving a solid
appearance and flicker-free window redraws), while others are inherited
from the old Mac OS operating system (the single system-wide menu-bar). mac ox10.3v introduced features to improve usability including expose, which is designed to make finding open windows easier.
With mac os x v 10.4new features were added, including dashboard. (a virtual alternate desktop for mini specific-purpose applications) and a search tool called spotlight which provides users with an option for searching through files instead of browsing through folders.