The Xerox PARC user interface consisted of graphical elements such as windows, menus, radio buttons, and check boxes. The concept of icons was later introduced by David Canfield Smith, who had written a thesis on the subject under the guidance of Kay. The PARC user interface employs a pointing device along with a keyboard. These aspects can be emphasized by using the alternative term and acronym for "windows, icons, menus, pointing device" (WIMP). This effort culminated in the 1973 Xerox Alto, the first computer with a GUI, though the system never reached commercial production.