In computing, a virtual desktop is a term used with respect to user interfaces, usually within the WIMP paradigm, to describe ways in which the virtual space of a computer's desktop environment is expanded beyond the physical limits of the screen's display area through the use of software. This compensates limits of the desktop area and is helpful in reducing clutter of running graphical applications. There are two major approaches to expanding the virtual area of the screen. Switchable virtual desktops allow the user to make virtual copies of their desktop view-port and switch between them, with open windows existing on single virtual desktops. Another approach is to expand the size of a single virtual screen beyond the size of the physical viewing device. Typically, scrolling/panning a subsection of the virtual desktop into view is used to navigate an oversized virtual desktop. Overview Switching desktops Switchable desktops were designed and implemented at Xerox PARC as "Rooms" by Austin Henderson and Stuart Card in 1986 and (unknowingly to the authors until their publication) was conceptually similar to earlier work by Patrick Peter Chan in 1984. This work was covered by a US patent. Switchable desktops were introduced to a much larger audience by Tom LaStrange in swm (the Solbourne Window Manager, for the X Window System) in 1989. ("Virtual Desktop" was originally a trademark of Solbourne Computer.) 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 “context”. They are then only accessible to the user if that particular context is enabled. A switching desktop provides a pager 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. Several X window managers provide switching desktops. 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 view-port. 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