rbowen writes "Apache OpenOffice 3.4.1 has averaged 138,928 downloads per day. That is an average value to the public of $21 million per day, as calculated by savings over buying the competing product. Or $7.61 billion (7.61 thousand million) per year." Link to Original Source
The reason that every major university maintains a department of
mathematics is that it's cheaper than institutionalizing all those people.