In computing, a is a term used with respect to user interfaces, usually within the WIMP paradigm, to describe ways in which the size of a 's is expanded beyond the physical limits of the screen's real estate through the use of software.

Switchable desktops were designed and implemented at Xerox PARC as "Rooms" by D.A. Henderson and Stuart Card in 1986[1] based upon work by Patrick P. Chan in 1984. This work was covered by a US patent[2].

Switchable desktops were introduced to a much larger audience by Tom LaStrange in (the Solbourne Manager, for the ) in 1989. ("Virtual Desktop" was originally a trademark of Solbourne Computer.)[3] Rather than simply being placed at an x, y position on the computer's display, windows of running applications are then placed at x, y positions on a given virtual desktop ³context´. They are then only accessible to the user if that particular context is enabled. A switching desktop provides a way for the user to switch between "contexts", or pages of screen space, only one of which can be displayed on the computer's display at any given time.

Oversized Desktops

Other kinds of virtual desktop environments do not offer discrete virtual screens, but instead make it possible to pan around a desktop that is larger than the available hardware is capable of displaying. This facility is sometimes referred to as panning, scrolling desktops or viewport. For example, if a graphics card has a maximum resolution that is higher than the monitor's display resolution, the virtual desktop manager may allow windows to be placed "off the edge" of the screen. The user can then scroll to them by moving the mouse pointer to the edge of the display. The visible part of the larger virtual screen is called a viewport.

implementation

Virtual desktop managers are available for most graphical operating systems and offer various features, such as placing different wallpapers for each virtual desktop and use of hotkeys or other convenient methods to allow the user to switch amongst the different screens.

Amiga

The first platform to implement multiple desktop display as a hardware feature was 1000, released in 1985. The Amiga moved on to succeed in the consumer and video production market. All supported multiple in-memory screens displayed concurrently via the use of the graphics co-processor, AKA the "Copper". The Copper was a simple processor whose operations waited for a screen position, wrote to hardware registers (including display memory fetch position), conditionally skipped an instruction, or performed No OPeration [NOP]. Using the GUI implemented in system ROM API's, programs could transparently display multiple independent screens, from non-consecutive memory, without moving the memory. This hardware-based scrolling does not use blitting, but something more like what is sometimes called hardware panning. The video output is simply told (once, or many times) where to display (scanline) and from what screen memory address. A screen can move to any position, or display any portion, by modifying the wait, or fetch position. Typically a single byte value. The Copperlist did need to be sorted in vertical and horizontal wait position in order to function. Note: See http://www.faqs.org/faqs/amiga/books/ for a list of reference material.

Each desktop or 'screen' could have its own colour depth (number of available colours) and resolution, including use of interlacing. The display chipset ('graphics card' on a PC) could switch between these desktop modes on the fly, and during the drawing of a single screen, usually with three pixel deep line between each desktop shown on the screen. However, if one interlaced (flickering) desktop was displayed, all desktops onscreen would be similarly affected.

Some programs, VWorlds (an astronomy simulator) being an example, used the multiple desktops feature to overlay a set of controls over the main display screen. The controls could then be dragged up and down in order to show more or less of the main display.

In 1988 with the release of the Amiga A2024[4] monitor which added Amiga a vast choice of displaying various high-resolutions and in addition with Amiga graphic cards resolutions on which to run a Higher Resolution Workbench Desktop. Previous version only supported PAL or NTSC display modes.

[edit] X Window System (Linux and )

Almost all Unix-like systems use the X Window System to provide their windowing environment.

The X Window System is unique in that the decoration, placement, and management of windows are handled by a separate, replaceable program known as a . This separation allowed third-party developers to introduce a host of different window manager features, resulting in the early development of virtual desktop capabilities in X. Many of today's X window managers now include virtual desktop capabilities.

Configurations range from as few as two virtual desktops to several hundred. The most popular desktop environments, GNOME and KDE, use multiple virtual desktops (two or four by default). Some window managers, like FVWM, offer separate "desks" that allow the user to organize applications even further. For example, a user may have separate desks labeled "Work" and "Home", with the same programs running on both desks, but fulfilling different functions. Some window managers such as support "tagging" where applications can be configured to always launch on a particular, named desktop, supporting automatic organization and easy navigation.

[edit] OS/2

IBM's personal computer OS/2 included multiple desktops (up to 4 natively) in the OS/2 Warp 4 release in 1996. [edit] Windows

Microsoft Windows does not implement virtual desktops at installation time. Historically video card implementors have provided this functionality, such as Nvidia's nView product.

Currently, Microsoft offers a utility called Desktops which allows users running Windows XP or Windows Server 2003 or later operating systems to run applications on up to 4 virtual desktops.[5]

Microsoft had previously provided a Virtual Desktop PowerToy (for Windows XP [1]), a software-based virtual desktop manager, which simulates many desktops, by minimizing and maximizing windows in groups, each group being a different desktop. However, the functionality provided is less comprehensive than that of many other virtual desktop solutions (e. g. maintain a window in a given desktop even when its application bar flashes, etc.). Application compatibility problems are common, because application developers do not expect virtual desktops to be in use on the Windows platform.

Users of can use third-party software for advanced virtual desktop visualization, such as 3D virtual desktop managers that emulate some of the eye-candy features available on .

Many desktop replacements for Windows, including LiteStep, bblean, GeoShell, SharpE, Emerge Desktop and others, support virtual desktops via optional modules.

Are you required to use Windows and wish you had the multiple desktop capability of Linux? Now you can organize your Windows desktop with up to 20 customizable, virtual desktops using a free utility called Dexpot. We briefly mentioned this software in our article 99 of the best Windows freeware programs you may not know of. In this two-part series, we will go through the different features of the program and how to use them.

Download Dexpot from http://www.dexpot.de/index.php?id=download.

Once you have installed Dexpot and run the program, an displays in the system tray.

Switching to Another Virtual Desktop

To see how virtual desktops work, we will start by switching to another virtual desktop. There are three ways to do this.

Switching Desktops Using the

Before switching desktops, open some programs, so you can see the effect of switching desktops. The initial desktop is Desktop 1 when the program is first installed. Therefore, any programs you open before switching desktops for the first time, are on Desktop 1.

Once you have some programs open, right-click on the Dexpot icon in the system tray to activate the pop-up menu. The currently active desktop has a check mark to the left of the desktop name. As an example, select Desktop 2 from the upper section of the pop-up menu.

You will notice the open programs disappear, including the buttons. Any programs or windows you open while on Desktop 2 only display when Desktop 2 is the active desktop. Open a program on Desktop 2. Now, switch back to Desktop 1 and you will see the programs on Desktop 1 become available again.

Switching Desktops Using the Desktop Manager

You can also switch desktops using the Desktop Manager. Right-click the Dexpot system tray icon and select Desktop Manager from the pop-up menu.

The Desktop Manager displays in the lower, right corner of the screen. The currently active desktop is outlined in the Desktop Manager. To switch to Desktop 2 using the Desktop Manager, just click on the icon labeled ³2´ on the manager.

To access the menu for the Desktop Manager, right-click on any empty space on the Desktop Manager. You can close the Desktop Manager using this menu by selecting Close from this menu.

You can make the icons on the Desktop Manager smaller using the Change icon size option.

You can add a button that allows you to access two options quickly by selecting the Show additional Button option. Initially, when Dexpot is first installed, the two actions that can be performed using the additional button are to view the Full-screen preview (single-click) and to Apply rules (double-click). The options available on this additional button can be customized in the settings, discussed later in this post.

Use the Show icons of active windows option to display the icon for the active program for each desktop on the Desktop Manager instead of the default computer icon. This allows you another quick way to see which desktop you want, by seeing which program is active on each desktop.

What is virtual desktop?

virtual desktop

Show me everything on Virtual desktop infrastructure and architecture

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What is a virtual desktop?

1. A virtual desktop is an individual user's interface in a virtualized environment.The virtualized desktop is stored on a remote server rather than locally.

Desktop virtualization software separates the physical machine from the software and presents an isolated operating system for users. Desktop virtualization tools include Microsoft Virtual PC, VMware Workstation and Parallels Desktop for Mac.

The benefits of desktop virtualization include:

y Cost savings because resources can be shared and allocated on an as-needed basis. y More efficient use of resources and energy. y Improved data integrity because backup is centralized. y Centralized administration. y Fewer compatibility issues.

Knowledge workers who use mostly business software applications are good candidates for desktop virtualization. The model is not generally viable for users with high resource demands.