Uses
As most computer users no longer are concerned with the details of controlling their computer's peripherals, the task for which the escape sequences were originally designed, the escape key was appropriated by application programmers, most often to mean Stop. This use continues today in Microsoft Windows's use of escape as a shortcut in dialog boxes for No, Quit, Exit, Cancel, or Abort, as well as a common shortcut key for the Stop button in many web browsers.
On machines running Microsoft Windows, prior to the implementation of the Windows key on keyboards, the typical practice for invoking the "start" button was to hold down the control key and press escape. This key combination still works as of Windows 7.
Microsoft Windows makes use of "Esc" for many key shortcuts. Many of these shortcuts have been present since Windows 3.0, through Windows XP, Windows Vista, and Windows 7.
In OS X, "Esc" usually closes or cancels a dialog box or sheet. The ⌘ Command+⌥ Option+Esc combination opens the Force Quit dialog box, allowing users to end non-responsive programs. Another use for the Esc key, in combination with the Command key, is switching to Front Row, if installed.
In most computer games, the escape key is used as a pause button and/or as a way to bring up the in-game menu, usually containing ways to exit the program.
In the vi family of text editors, escape is used to switch modes. This usage is due to escape being conveniently placed in what is now the tab position on the ADM3A terminal keyboard used to develop vi, though it is now inconveniently placed. This is similar to how the extensive modifier keys in emacs were easily used on the original keyboard, being placed together, but these keys have now been spread around the keyboard, becoming more difficult to use.
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