Well, if we're going to have fun with "first" claims, there's a
Washington Post article by Kenneth Baer that contains the following
interesting claim:
"Computers were quickly becoming more pervasive, too. VisiCalc, an
early spreadsheet program, was introduced in 1978 and quickly became
the first commercially successful piece of software"
Read the article here:
http://www.statesman.com/opinion/content/editorial/stories/07/20/0720b
aer_edit.html
BTW, Baer is a former speechwriter for Al Gore.
Cheers,
Chuck