In computing, a theme is a preset package containing graphical appearance details, used to customize the look and feel of (typically) an operating system, widget set or window manager.
Graphics themes for individual applications are often referred to as skins, and the words are often used equivalently, the primary difference being one of scope.
Themes are often used to change the appearance of a wide range of things at once, which makes them much less granular than allowing the user to set each option individually. For example, you might want the window-borders from a particular theme, but installing it would also alter your desktop background.
One method for dealing with this is to allow the user to select which parts of the theme they want to load, for example in Windows 98, you could load the background and screensaver from a theme, but leave your icons and sounds untouched.
- IceWM uses themes to customise its taskbar, window borders, and time format
- GNOME and KDE use two independent sets of themes: one to alter the appearance of buttons, scrollbars, list elements, (for example to specify glassy-effect pushbuttons or square ones), and another theme to customise the appearance of windows (for example, window borders and title bars).
- Mac OS is themeable through third party applications, such as Kaleidoscope and ShapeShifter. Apple had planned to release system themes in version 8 of their OS, but they were removed at the last minute.
- WindowMaker can store colors for icons, menus, and window-borders in a theme, but this is independent of the wallpaper settings (and WindowMaker has no taskbar to customise)
- Windows 98 and Windows Me came with themes such as "nature", "space", etc. which contained desktop backgrounds, icons, sounds, colors, and cursors. This was also provided by Plus! for Windows 95 and the theme program also in the VALUEADD for Office 97.
- Windows XP introduced several new themes, including Luna and Royale, which were both very different from the Windows "Classic" look in previous versions of windows.
- Windows Vista introduced a new theme called Aero which aims to give the user a cleaner and sleeker look to windows. However, some older themes like XP's Luna have been removed.