Unity

Unity is an alternative shell for the GNOME desktop environment, developed by Canonical in its Ayatana project. It consists of several components including the Launcher, Dash, lenses, Panel, indicators, Notify OSD and Overlay Scrollbar. Unity available in two implementations: 'Unity' is the 3D accelerated version, which uses Compiz window manager and Nux toolkit; and 'Unity 2D' is a lighter alternative, which uses Metacity window manager and Qt toolkit.

External resources

 * Unity article in Arch Linux Wiki