modules to provide features as required. Rollup A rollup facility enables windows to appear as just a titlebar on the desktop. Root Menu Some window managers provide a root menu, which appears when the root window or desktop background is touched. Shortcuts Some window managers provide a shortcut facility that lets users place icons on the root window that access specific programs or facilities. Tabbed Windows Some window managers provide a tabbed windows facility that groups applications together in common frames. Task Switching The window manager may provide various task switching facilities that let the user change the currently focused application, including: Changing the mouse focus using a pointing device Keyboard task switching facilities (for example, by pressing Alt-Tab) Clicking on the task in a taskbar or taskpanel Taskbar Some window managers provide a taskbar that shows running applications. The taskbar may show all applications that are running including those that have been minimized, and may provide the facility to switch focus between them. The taskbar may be incorporated into a menubar on some window managers. Task Panel A task panel is similar to a taskbar, but appears as a floating panel, rather than a horizontal or vertical bar. Start Button A start button is a desktop widget that provides a menu of programs that can be launched. The start button is typically placed on a menubar at the bottom of the screen. Notification Area A Notification Area is used to display icons for system and program features that have no desktop window. It contains mainly icons to indicate status information and notifications such as arrival of a new mail message. Some systems may also show a clock in the Notification Area. Title Bars A titlebar is a window decoration component some window managers provide at the top of each window. The titlebar is typically used to display the name of the application, or the name of the open document, and may provide title bar buttons for minimizing, maximizing, closing or rolling up of application windows. Title Bar Buttons Title bar buttons are included in the titlebar of some window managers, and provide the facility to minimize, maximize, rollup or close application windows. Some window managers may display the titlebar buttons in the taskbar or task panel, rather than in a titlebar. Virtual Desktop A virtual desktop (also called a scrolling desktop) is a facility some window managers provided that