Why develpoers spend tons of time working on open source projects

I wrote a couple nifty After Dark screensavers back in the day, as well as a test harness that made it easier to debug them. I released the source code for all of them.

My former employer, Dave Johnson of Working Software, repeatedly urged me not to write any software that I was not paid to write.

I wrote those screensavers, and gave them away because I enjoyed the experience.

I still have a shareware CD from Japan, its shrinkwrap unopened, that came with a cover letter that said "Dear Great Soft-Maker".

That one letter made it all worthwhile.