A shell interface designed for the GNOME desktop environment running on the Ubuntu operating system. As a shell interface, Unity provides the underlying Ubuntu OS with a distinct, consistent look and feel while providing functionality for working with applications within the operating system.
Unity first debuted in June 2010 in the netbook edition of Ubuntu 10.10, and it became the default desktop in place of the GNOME Shell with the release of Ubuntu 11.04 (codenamed Natty Narwhal). The next major release of Unity, version 4.x, will be included in Ubuntu 11.10 (codenamed Oneiric Ocelot), which is scheduled to go live in October 2011.
Unity may also refer to a development tool for creating 3D video games that can run on Microsoft Windows, Mac OS X, iPad, iPhone, Android, Xbox 360, PlayStation 3 and Nintendo Wii platforms. Some of the more popular games developed using Unity include Battlestar Galactica, M.U.S.E., ShadowGun and Zombieville USA.