Unity is a graphical shell for the GNOME desktop environment originally developed by Canonical Ltd. for its Ubuntu operating system. It debuted in 2010 in the netbook edition of Ubuntu 10.10. Since 2017, its development was taken over by the Unity7 Maintainers (Unity7) and UBports (Lomiri, formerly known as Unity8).
Unity7 is the default desktop environment in Ubuntu Unity, an official flavor of Ubuntu since 2022. Ubuntu Unity and Unity7 Maintainers have started working on the successor of Unity7, UnityX.
It was part of the Ayatana project, an initiative with the stated intention of improving the user experience within Ubuntu. It was initially designed to make more efficient use of space given the limited screen size of netbooks, including, for example, a vertical application switcher called the launcher, and a space-saving horizontal multipurpose top menu bar. Unlike GNOME, KDE Plasma, Xfce, or LXDE, Unity is not a collection of applications. It is designed to use existing programs.
The Unity user interface consists of several components:
Top menu bar: a multipurpose top bar, saving space, and containing:
the menu bar of the active application
the title bar of the main window of the active application, including the maximize, minimize and exit buttons
the session menu, including the global system settings, logout, and shut down
the diverse global notification indicators including the time, weather, and the state of the underlying system.
Launcher: a taskbar. Multiple instances of an application are grouped under the same icon, with an indicator showing how many instances are open. The user has a choice whether or not to lock an application to the launcher. If it is not locked, an application may be started using the Dash or via a separately installed menu.
Quicklist: the accessible menu of launcher items
Dash: a desktop search utility that enables searching for information both locally (e.g. installed applications, recent files, or bookmarks) and online (e.g. Twitter or Google Docs). It displays previews of the results.