The case of LaTeX (Score 5, Interesting)

The case of everyones favorite macro package for everyones favorite document typesetting system, LaTeX, might be most convincing for the stance that sometimes it's better to sell support than to sell software. From an interview with the author of LaTeX, Leslie Lamport:

"GMZ: Was this always meant to be free software ? Did you ever try to "get rich" with it? Do you regret that you didn't?
LL: At the time, it never really occurred to me that people would pay money for software. I certainly didn't think that people would pay money for a book about software. Fortunately, Peter Gordon at Addison-Wesley convinced me to turn the LaTeX manual into a book. In retrospect, I think I made more money by giving the software away and selling the book than I would have by trying to sell the software. I don't think TeX and LaTeX would have become popular had they not been free. Indeed, I think most users would have been happier with Scribe. Had Scribe been free and had it continued to be supported, I suspect it would have won out over TeX. On the other hand, I think it would have been supplanted more quickly by Word than TeX has been." (From TUGboat 22 (2001)

Just a very succesful case of money made out of free/open source software that is often overlooked (and maybe one of the oldest cases as well!)