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6 of 7 it's already tagged code golf

Write a hello world GUI program that closes itself after three seconds

Please read the rules, and the bold areas as well.

Write a program in any language, so long as it has GUI support for a window system (cannot be text-consoles, etc., and must be a GUI/toolkit/window).

The program must say hello world in any manner (splash image, menu bar, status bar, title, video, message box, other widget stuff, etc.), so long as a GUI-compliant window appears and shows this text for three seconds. The person who can code this in the least amount of code used, counted in bytes, will take the cake.