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 year after. Aqua is the successor to Platinum, which was used in Mac OS 8, Mac OS 9 and Mac OS X Server 1.2. The appearance of Aqua has changed frequently over the years, most recently and drastically with the release of OS X Yosemite in 2014 which introduced a flatter look and did away with the gel-like controls and metal-like components.