Crunching the numbers on the pay-what-you-like Humble Indie Bundle package, the Wolfire people noticed a curious thing: Linux users contribute twice as much as Windows users. "So far, the average Mac user is donating 40% more, and the average Linux user is donating 100% more!" I've got a half-formed theory in my head that living in a world where people are generous and share makes you generous and sharing, while living in a world where people are stingy and proprietary makes you stingy and proprietary. This would be why Econ students play the Ultimatum Game more cruelly than civilians.