Windows XP visual styles
Windows XP visual styles are customizations of the graphical user interface of Windows XP. "Luna", "Royale", "Zune", and "Embedded" are codenames of the official visual styles designed for Windows XP by Microsoft. Since Windows XP, themes include the choice of visual styles as well. By default, "Luna" is preinstalled on Windows XP Home and Professional editions, "Royale" is preinstalled on Windows XP Media Center Edition and "Embedded" is preinstalled on Windows Embedded Standard 2009 and Windows Embedded POSReady 2009. In addition to the preinstalled visual styles, Microsoft has released additional ones for download. Third parties have also released visual styles, though these require modification of core Windows components to work. Visual styles are compatible with all Windows XP editions except Starter Edition.
Compared to Desktop Themes in previous versions of Windows such as Microsoft Plus! for Windows 95, Windows 98, and Windows Me, the new visual styles have a greater emphasis on the graphical appeal of the operating system, using saturated colors and bitmaps throughout the interface, with rounded corners for windows.
The visual styles API was substantially expanded in Windows Vista and later. Nevertheless, the API remained heavily underdocumented.