Aqua (user interface)

Aqua is the graphical user interface, design language and visual theme of Apple's macOS operating system. It was originally based on the theme of water, with droplet-like components and a liberal use of reflection effects and translucency. Its goal is to "incorporate color, depth, translucence, and complex textures into a visually appealing interface" in macOS applications. At its introduction, Steve Jobs noted that "... it's liquid, one of the design goals was when you saw it you wanted to lick it". Aqua was first introduced at the 2000 Macworld Conference & Expo in San Francisco. Its first appearance in a commercial product was in the July 2000 release of iMovie 2, followed by Mac OS X 10.0 the following year. Aqua is the successor to Platinum, which was used in Mac OS 8, Mac OS 9, and developer releases of Rhapsody (including Mac OS X Server 1.2). The appearance of Aqua has changed frequently over the years, most recently and drastically with the release of macOS Big Sur in 2020 which Apple calls the "biggest design upgrade since the introduction of Mac OS X." For years, Apple had been trying and failing to produce a next-generation Mac OS operating system, including projects code-named Pink, Taligent, and Copland. Mac OS X was ultimately built on NeXTSTEP, after Apple purchased NeXT and its CEO, Steve Jobs, returned to Apple, the company he had cofounded. Early versions of Mac OS X, called Rhapsody (operating system), was a developer release that had an interim user interface, blending MacOS 8's "Platinum" and OpenStep looks. The Rhapsody approach was ultimately abandoned, and the new operating system was dubbed Mac OS X in 1998. Early developer previews of Mac OS X shipped with an interface similar to Rhapsody, combining classic Mac OS and NextStep. The final operating system interface, Aqua, would be unveiled at Macworld Expo in January 2000. Aqua uses blue, white, and gray as the principal colors throughout its style. Window toolbars, window backgrounds, buttons, menus and other interface elements are all found in either of these colors.