MICROSOFT
'(<a href="http://www.j-archive.com/media/2009-10-06_DJ_25.wmv">Sarah of the Clue Crew plays with a mouse on a computer at a museum exhibit at Microsoft Research in Redmond, WA.</a>)  One of the reasons windows sold a million copies a month in the '90s was the GUI, short for this, which let users communicate with the computer via symbols & icons'
graphical user interface