StickyKeys is an accessibility feature to help computer users who have physical disabilities, but it is also used by others as a means to reduce repetitive strain injury (or a syndrome called the Emacs Pinky). It essentially serializes keystrokes instead of pressing multiple keys at a time: StickyKeys allows the user to press and release a modifier key, such as Shift, Ctrl, Alt, or the Windows key, and have it remain active until any other key is pressed.
StickyKeys was first available with the availability of the Extension Easy Access with Mac OS version 6, which also featured moving the mouse cursor with the Keyboard.
Microsoft added StickyKeys to their Windows operating system with Windows 95 and is also used on later versions.[1]
It is also now present on Unix/X11 (there called AccessX) and Mac OS X.[2][3]
In Windows, to toggle on the StickyKeys feature, the user presses the Shift key 5 times in a row or press left Alt, left Shift and Print Scrn, and to turn it off press both shift keys at the same time. When activated, a dialog box appears, and the computer makes an internal chirp.[4] This is consistent with the activation sequence on the Macintosh. The activation is indicated by a small icon in the menu bar.