In computing, the taskbar is a term for the application desktop bar which is used to launch and monitor applications in Microsoft Windows 95 and later versions. Other desktop environments also feature similar interface elements.
In Windows, the default location for the taskbar is at the bottom of the screen, and from left to right it contains by default the Start menu, Quick Launch bar, taskbar buttons and notification area (commonly, and incorrectly, referred to as the system tray). With the release of Windows XP, Microsoft changed the behavior of the taskbar to take advantage of Fitts' law.
- The Start menu contains commands that can access programs, documents, and settings. These commands include Programs, Documents, Settings, Find, Help, Run, and Shut Down.
- The Quick Launch bar, introduced with Internet Explorer 4, contains shortcuts to applications. Windows provides default entries, such as Internet Explorer, and the user or third-party software may add any further shortcuts that they choose. A single click on the application's icon in this area launches the application. This section may not always be present: for example it is absent by default in Windows XP, although it can be enabled.
- The Windows Shell places a taskbar button on the taskbar whenever an application creates an unowned window: that is, a window that doesn't have a parent and that is created according to normal Windows UI guidelines. Typically all SDI applications have a single taskbar button for each open window, although modal windows may also appear there. Windows XP introduced taskbar grouping, which can group the taskbar buttons of several windows from the same application into a single button. This button pops up a menu listing all the grouped windows when clicked. This keeps the taskbar from being overcrowded when many windows are open at once.
- The last part of the taskbar is called the notification area. It contains mainly status notifications, though some programs, such as Winamp, use it for minimised windows. The clock by default appears here, and applications can put icons in the notification area to indicate the status of an operation or to notify the user about an event. For example, an application might put a printer icon in the status area to show that a print job is under way, or a display driver application may provide quick access to various screen resolutions. In Windows XP and newer Windows versions, the user can choose to permanently display or hide some icons, or hide them if inactive for some time. A button allows the user to reveal all the icons. Optionally, a clock can be displayed in the notification area. A class of utilities typically called taskbar clock replacements can replace the Windows XP taskbar clock with a clock with more features.
Other toolbars may be added to the taskbar, and it can also be hidden, placed on top of other applications, or moved to the side or the top of the screen.
- Upon opening the Taskbar properties on Windows 95 and Windows 98 whilst holding down the CTRL key, an extra tab for DeskBar Options is shown, but no part of it can be used. The DeskBar option was a feature that never got included within these versions of Windows.
Other desktop environments
Windows is not the only operating system with a taskbar: similar bars are present in various Linux desktop environments. The Dock, as featured in Mac OS X and its predecessor NEXTSTEP, is also a kind of taskbar. The Mac OS X Dock is application-oriented instead of window-oriented. Each running application is represented by one icon in the Dock regardless of how many windows it has on screen. A textual menu can be opened by right-clicking on the dock icon that gives access to an application's windows, among other functions determined by the app. Minimised windows also appear in the dock, in the rightmost section, represented by a graphical thumbnail.
The first known implementation of the taskbar concept is seen in Acorn's Arthur operating system, which was released in 1987 for their Archimedes computer. It is called the Iconbar and remains an essential part of Arthur's succeeding RISC OS operating system. The Iconbar holds icons which represent mounted disc drives and RAM discs, running applications and system utilities. These icons have their own context-sensitive menus and support drag and drop behaviour. It should be noted that Windows 1.00, released in 1985 (two years earlier than Arthur), also sported a variant of the taskbar. Running tasks were iconified in the bottom panel. There was no notification area, though.Windows 2.x and 3.x had no taskbar, but showed minimised running tasks on the Desktop.
In various KDE distributions, the taskbar is run by the Kicker program, and consists of two parts: the panel and the taskbar. The panel is a control bar across the bottom of the screen, which is used to find and launch applications and navigate among windows and desktops. It contains the menu, which is comparable to the Windows start menu; the disk navigator, which allows access to the file system by menus (a similar thing can be done in Windows); and the desktop pager, which changes between desktops. The last item is not possible in Windows by default. As with the Windows 'Quick Launch bar', additional buttons can be added to the KDE panel, to quickly open applications, directories, and URLs. The second part is the taskbar runs across the top of the screen and helps keep track of running applications. This is similar to the 'Taskbar buttons' area of the Windows taskbar.
Similarly, the GNOME desktop environment uses its own type of taskbar, known as panels (the program responsible for them is therefore called gnome-panel). By default, GNOME usually contains two full-width panels at the top and bottom of the screen. The top panel usually contains navigation menus labelled Applications, Places, and System in that order. These menus hold links to common applications, areas of the file system, and system preferences and administration utilities, respectively. The top panel usually contains a clock and notification area, which can double as a sort of dock, as well.
The bottom panel is commonly empty by default, other than a set of buttons to navigate between desktops and a button to minimise all windows and show the desktop, due to its use in the navigation between windows (windows minimise to the bottom panel by default).
These panels can be populated with other completely customizable menus and buttons, including new menus, search boxes, and icons to perform quick-launch like functions. Other applications can also be attached to the panels, and the panels are highly reconfigurable: anything on these panels can be moved, removed, or configured in other ways. For example, a dedicated Windows user migrating to GNU/Linux might move the menus usually posed in the top panel into a 'start' menu on the bottom panel as well as moving the notification area into the place normally posed by the Windows notification area, then remove the top panel altogether, in order to emulate Windows.