[progval]

I do, as much as I can.

The main reason is that it's important for me to contribute to the common good regardless of monetary reasons, if I can afford to do so. This is true both at a moral/political level, and at a personal level (feeling useful).

It's also a way to give back to projects I use, as I can't donate money to all of them as much as they are worth.

I also like to program just for fun (ie. not useful stuff), and today it's as easy to make my useless stuff open source rather than keeping it private; so I might as well make it open source, because sometimes other people actually find it useful.