In computing, a taskbar is a bar displayed on a full edge of a GUI desktop that is used to launch and monitor running applications. Microsoft introduced the taskbar in Windows 95 in 1995 and the feature has been a defining aspect of Microsoft Windows's graphical user interface and many other operating systems and desktop environments since.
Early implementations 
Windows 1.0 
Windows 1.0, released in 1986, features a horizontal bar located at the bottom of the screen where running programs reside when minimized (referred to as "iconization" at the time), represented by icons. A window can be minimized by double-clicking its title bar, dragging it onto an empty spot on the bar, or by issuing a command from one of its menus. A minimized window is restored by double-clicking its icon or dragging the icon out of the bar.
The bar features multiple slots for icons and expands vertically to provide with more rows as more slots are needed. Its color is the same as that of the screen background, which can be customized. Minimized windows can be freely placed in any of the empty slots. Program windows cannot overlap the bar unless maximized.
Appearance of the bar used for holding minimized windows in Windows 1.0
Acorn Computers 
Another early implementation can be seen in Acorn Computers 1987 Arthur operating system. It is called the Icon bar 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.
Appearance of Acorn's icon bar in 1987 under Arthur, after launching a number of devices and applications
AmigaOS featured various implementations of taskbar concept, and this inheritance is present also in its successors (AmigaOS 4.0, AROS, MorphOS). There could be AppIcons (Quick Launch Icons) lying on the windows manager desktop of Amiga (called Workbench) since AmigaOS 2.04 (in 1991); also very appreciated in Amiga are "dock" utilities, just as like as in MacOS. For example Amidock born as third party utility, has then being integrated into AmigaOS 3.9 (2000), and an enhanced PPC Amidock version runs into AmigaOS 4.0. As long as AmigaOS interface is highly customizable, it could also being integrated with taskbar utilities whose aspect could be more or less similar in aspect to the taskbars of Windows. For example AmiKit is a freeware compilation of more than 300 Amiga programs. It could be used to enhance experience of native Amigaos 3.9 or any version of AmigaOS 3.5 or 3.9 running into Windows Amiga Emulator WinUAE. Amikit features a windows-like taskbar utility (called Amistart) that is being loaded by default at startup. AROS operating system has its version of Amistart too that is provided with the OS and free to be installed by the users, while MorphOS has being equipped with a docking utility just as like as AmigaOS or MacOS.
Microsoft Windows 
The default settings for the taskbar in Microsoft Windows place it at the bottom of the screen and includes from left to right the Start menu button, Quick Launch bar, taskbar buttons, and notification area. The Quick Launch toolbar was added with the Internet Explorer 4 shell update, and is not enabled by default in Windows XP. Windows 7 removed the Quick Launch feature in favor of pinning applications to the taskbar itself. In Windows 8, the Start menu button has been removed in favor of the hotspot to go back to the Start screen.
The taskbar was originally developed as a feature of Windows 95, but it was based on a similar user interface feature called the tray that was developed as part of Microsoft's Cairo project.
With the release of Windows XP, Microsoft changed the behavior of the taskbar to take advantage of Fitts's law.
The taskbar in Windows 7
hides application names in favor of large icons that can be "pinned" to the taskbar even when not running. Unlike Windows Vista
and Windows XP
's notification area, users have a choice to show all their notifications or get a small pop-up window, showing the user notifications without expanding.
A standard Windows XP
taskbar with multiple tasks running. Note the Quick Launch toolbar, introduced in Windows 98. When the notification area is full, it can be expanded.
The original implementation of the Windows taskbar in Windows 95
Taskbar elements 
- The Start button, a mainstay of Windows prior to Windows Server 2012, this button invokes Start menu.
- The Quick Launch bar, introduced with Windows 98 (also for separate download for Windows 95 and Windows NT 4.0 with Windows Desktop Update for Internet Explorer 4), contains shortcuts to applications. Windows provides default entries, such as Launch Internet Explorer Browser, 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 turned off by default in Windows XP and Windows 7.
- 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 user interface guidelines. Typically all Single Document Interface applications have a single taskbar button for each open window, although modal windows may also appear there.
- Windows 98 and Windows Desktop Update for Windows 95 introduced the ability to minimize foreground windows by clicking their button on the taskbar.
- Windows 2000 introduced balloon notifications.
- Windows Me added an option to disable moving or resizing the taskbar.
- 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.
- Windows Vista introduced window previews which show thumbnail views of the application in real-time. This capability is provided by the Desktop Window Manager. Start menu tooltip no longer says "Click here to begin". Now, says simply "Start".
- Windows 7 introduced jumplists which are menus that provide shortcuts to recently opened documents, frequently opened documents, folders paths (in case of Windows Explorer), or various options (called Tasks) which apply to that specific program or pinned website shortcut. Jump lists appear when the user right-clicks on an icon in the taskbar or drags the icon upwards with the mouse left click. Recent and frequent files and folders can be pinned inside the jump list.
- Windows 7 introduced the ability to pin applications to the taskbar so that buttons for launching them appear when they are not running. Previously, the Quick launch was used to pin applications to the taskbar; however, running programs appeared as a separate button.
- Windows 7 removed several classic taskbar features.
- Deskbands are minimized functional, long-running programs, such as Windows Media Player. Programs that minimize to deskbands aren't displayed in the taskbar.
- The notification area is the portion of the taskbar that displays icons for system and program features that have no presence on the desktop as well as the time and the volume icon. It contains mainly icons that show status information, though some programs, such as Winamp, use it for minimized windows. By default, this is located in the bottom-right of the primary monitor (or bottom-left on languages of Windows that use right-to-left reading order), or at the bottom of the taskbar if docked vertically. The clock 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. The notification area is commonly referred to as the system tray, which Microsoft states is wrong, although the term is sometimes used in Microsoft documentation, articles, and software descriptions. Raymond Chen suggests the confusion originated with systray.exe, a small application that controlled some icons within the notification area in Windows 95. The notification area is also referred to as the status area by Microsoft.
- In older versions of Windows the notification area icons were limited to 16 colors. Windows Me added support for high color notification area icons.
- Starting with Windows XP, the user can choose to always show or hide some icons, or hide them if inactive for some time. A button allows the user to reveal all the icons.
- Starting with Windows Vista, the taskbar notification area is split into two areas; one reserved for system icons including clock, volume, network and power. The other is for applications.
The Windows taskbar can be modified by users in several ways. The position of the taskbar can be changed to appear on any edge of the primary display. Up to and including Windows Server 2008, the taskbar is constrained to single display, although third-party utilities such as UltraMon allow it to span multiple displays. When the taskbar is displayed vertically on versions of Windows prior to Windows Vista, the Start menu button will only display the text "Start" or translated equivalent if the taskbar is wide enough to show the full text. However, the edge of the taskbar (in any position) can be dragged to control its height (width for a vertical taskbar); this is especially useful for a vertical taskbar to show window titles next to the window icons.
Users can resize the height (or width when displayed vertically) of the taskbar up to half of the display area. To avoid inadverdent resizing or repositioning of the taskbar, Windows XP and later lock the taskbar by default. When unlocked, "grips" are displayed next to the movable elements which allow grabbing with the mouse to move and size. These grips slightly decrease amount of available space in the taskbar.
The taskbar as a whole can be hidden until the mouse pointer is moved to the display edge, or has keyboard focus..
The charms 
Windows 8 adds a secondary bar similar to taskbar which is referred to by the items on it, called "charms" or "the charms" (lowercase). They are invoked by swiping the right edge of the touchpad or moving the mouse cursor to the top right or bottom right corner of the screen. There are five charms on this taskbar: Search, Share, Start, Devices and Settings. Except Start, each charms is a sidebar whose contents changes, depending on the application that has focus. Start is the same button that once resided on taskbar. It invokes Start screen.
Desktop toolbars 
Other toolbars, known as "Deskbands", may be added to the taskbar. Windows includes the following deskbands but does not display them by default (except the Quick Launch toolbar in certain versions and configurations).
- Address. Contains an address bar similar to that found in Internet Explorer.
- Windows Media Player. Optionally shown when the Windows Media Player is minimized.
- Links. Shortcuts to items located in the users Links folder. Usually shortcuts to internet sites.
- Tablet PC Input Panel. Contains a button to show the Tablet PC input panel for ink text entry.
- Desktop. Contains shortcuts to items contained on the users desktop. Since the taskbar is always shown, this provides easy access to desktop items without having to minimize applications.
- Quick Launch. Contains shortcuts to Internet Explorer, email applications and a link to display the desktop. Windows Vista adds a link to the Flip 3D feature.
- Language. Contains shortcuts to quickly change the desired language for the keyboard to follow.
In addition to deskbands, Windows supports "Application Desktop Toolbars" (also called "appbands") that supports creating additional toolbars that can dock to any side of the screen, and cannot be overlaid by other applications.
Users can add additional toolbars that display the contents of folders. The display for toolbars that represent folder items (such as Links, Desktop and Quick Launch) can be changed to show large icons and the text for each item. Prior to Windows Vista, the Desktop Toolbars could be dragged off the taskbar and float independently, or docked to a display edge. Windows Vista greatly limited, but did not eliminate the ability to have desktop toolbar not attached to the taskbar. Windows 7 has deprecated the use of Floating Deskbands altogether: they only appear pinned into the Taskbar.
- 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 was never included within these versions of Windows.
Mac OS 
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. Minimized windows also appear in the dock, in the rightmost section, represented by a graphical thumbnail. The trash can is also represented in the Dock, as a universal metaphor for deletion. For example, dragging selected text to the trash should remove the text from the document and create a clipping file in the trash.
The right side of Mac OS X's Menu bar also contains several notification widgets and quick access functions, called Menu extras.
A dock in OS X v10.5
with a variety of applications
Unix-like operating systems 
In KDE distributions before Version 4, the taskbar is run by the Kicker program, which shows rectangular panels that can contain applets, one of which is the taskbar. Applets can be arbitrarily relocated, for instance, the notification area can be moved away from the taskbar. The bar can be placed not only at the bottom, but also at the top or (vertically) at the left or the right and its size can be altered (from 24 to 256 pixels), as well as the length in % of the screen size. And several other bars with various specific functions can be added in different locations, e.g., one bar at the left and one at the right or even overlapping (one fixed and one with automatic hiding). Since KDE Software_Compilation 4, the taskbar is implemented as a Plasma widget.
Standard layout in KDE 3.5.
Plasma panel being resized in KDE 4.3
In this Kicker layout the taskbar is located along the top screen edge, and most applets have been moved to a vertical panel (on the left) to conserve vertical space (especially significant for wide-screen monitors). The button with a cross closes the active window
Similarly, the GNOME desktop environment 2 used its own type of taskbar, known as panels (the program responsible for them is therefore called gnome-panel). By default, GNOME 2 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.
Default top panel in Ubuntu
Default bottom panel in Ubuntu
The bottom panel is commonly empty by default, other than a set of buttons to navigate between desktops and a button to minimize all windows and show the desktop, due to its use in the navigation between windows (windows minimize to the bottom panel by default).
These panels can be populated with other 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 contents of the panels can be moved, removed, or configured in other ways.
Today, the functionality in Gnome 2 has been replaced in Gnome 3 (Gnome Shell) with the Activities Overview. Rather than minimizing windows, windows are managed by being dragged and dropped in different workspaces. Apps can be added, removed, or launched from the Dash (similar to the Dock in OS X) on the left side of the Activities Overview. Extensions installed in Gnome Shell can bring some classic behaviors back.
Other Unix environments 
Window managers that provide an integrated taskbar include:
Programs that offer standalone taskbars for desktop environments or window managers without one include pypanel, fbpanel, perlpanel, tint2, and others.
- ^ Amiga Amidock Homepage
- ^ Amikit "preinstalled software environment" Homepage
- ^ US patent 5825357, Malamud, Marceau, Grauman, Levien, Oran, Bolnick, Barnes, Johnson, Scott, "Continuously accessible computer system interface", issued 1998-10-20, assigned to Microsoft Corporation
- ^ Kent Sullivan (April 17, 1996). "The Windows 95 User Interface: A Case Study in Usability Engineering". CHI 96 Design Briefs. Retrieved 2008-10-22.
- ^ a b Chen, Raymond (September 10, 2003). "Why do some people call the taskbar the "tray"?". The Old New Thing. Microsoft. Retrieved 2008-04-20.
- ^ Harris, Jensen (August 22, 2006). "Giving You Fitts". Jensen Harris: An Office User Interface Blog. Microsoft. Retrieved 2008-01-14.
- ^ Windows Vista Developer Center - The Windows desktop
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- ^ "How To Manipulate Icons in the System Tray with Visual Basic". 2004-07-15. Retrieved 2009-01-23.
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- ^ "How To Manipulate Icons in the System Tray with Visual Basic". Retrieved 2011-06-09.
- ^ Chen, Raymond (September 20, 2003). "When I dock my taskbar vertically, why does the word "Start" disappear?". The Old New Thing. Microsoft. Retrieved 2008-04-20.
- ^ "Differences with Windows XP Home Edition". Windows XP Resource Kit. Microsoft. November 3, 2005. Retrieved 2008-04-20.
- ^ "Cannot Move or Resize the Taskbar or Any Toolbars on the Taskbar (MSKB279774)". Knowledge Base. Microsoft. January 25, 2006. Retrieved 2008-04-20.
- ^ "Get to know Windows RT". Microsoft Surface support. Microsoft. Retrieved 4 January 2013.
- ^ "The charms: Search, Share, Start, Devices, and Settings". Windows 8 portal. Microsoft. Retrieved 4 January 2013.
- ^ "Overview". Windows 8 portal. Microsoft. Retrieved 4 January 2013.
- ^ "Notification Area". Windows Vista User Experience Guidelines. Microsoft.
- ^ "Using Application Desktop Toolbars". Microsoft.
- ^ Create a shortcut toolbar on the desktop
- ^ DeskBar Options Tab in Taskbar Properties Is Not Functional