From its inception, OS X had one, glaring problem - the desktop was useless. To be sure, it could be used, but one could never see it while working with more than a single window open.

Show Desktop seamlessly fixed OS X. One mouse-click, and the desktop is fully visible and usable! Amazing! Apple should add this functionality to OS X.

Uhhhh, then I got Panther, and Apple finally did add this functionality to OS X, but in a more elegant and far more useful implementation. So there is no reason at all for Show Desktop to exist. But the author deserves accolades for offering such great freeware back when it was needed.