If you haven't read it yet, go and read Eric S. Raymond's Homesteading the Noosphere which I found to be a fascinating read on the dynamics of the hacker culture (that's what he calls it. I think he's being more specific to the Open Source/Free Software culture which to me is a little different). In summary, Raymond tries to analyze and quantify the motivations of hackers.

If you look at it, hackers don't code for money. They code for prestige. The culture rewards people who write and give away good code, or who contribute to other projects, with a certain amount of respect and recognition. People who start new projects, especially in unclaimed knowledge territories (noospheres) that are useful, receive for recognition. Other contributors to a project share in the recognition, to a lesser extent of course, almost as if the founder gives some of his recognition to major contributors in return for their contributions.

There are three important (and ill-recognized) rules that hackers seem to follow. Don't fork projects, don't distribute your code changes if you aren't the project coordinator, don't remove people's names from the project history. All these three rules have traceable roots in the gift giving culture (the bigger the gifts, the more prestige).

Forking projects means having your name attached to multiple projects. Your code might break one of the forks, making you look bad. So you have to maintain tabs on multiple forks. But what if you don't? Then people split up into two camps and eventually one of the forks will dominate the sphere and become the official project, leaving the other fork (and all its contributors) forgotten. It's much safer to contribute to the current project than to try to fork it and go your own way.

One of the main powers of a project coordinator is in deciding what new code to include and when to release code. Open Source people don't mind if you take code and modify for your own use and the use of a specialized sphere of users. But release that code without consent of the project coordinator is a major faux pas. It comes down to you trying to fork a project by yourself, and hackers hate people who are not humble.

It's an interesting facet of gift giving cultures that along with giving bigger gifts, you also have to be humble. It makes sense to me intuitively. I respect people more if they contribute without making a big show of it, because then it makes it look like you did it for the attention. To a certain extent another gift giving culture is the entertainment industry. Hollywood stars contribute lots of money to various causes and you never hear about it unless some news people get wind of it. And that's ok. But if it looks like they are doing it for the attention, then people start making fun of them.

Back to hackers. Don't remove credits. Since this is a culture based on your prestige, and since the almost only way to gain prestige is to have your name down as a contributor, source code credits almost gain monetary value. Most of the free software licenses are quite liberal, but they all have clauses to make sure that you can't take someone's code and use it without crediting them.

I'm running out of space so I'll finish by saying that the gift-giving paradigm is pretty much how I do things also. I like making grand gestures by giving expensive gifts. And I like volunteering and doing "selfless" things. But it really all boils down to me trying to gain a certain amount of prestige, a reputation as a nice guy. And yet when people say what a great guy I am, I automatically say how my actions are not that significant, point out that other people make contributions, bring out my shortcomings as a balance. I didn't realize just how much I fit into the pattern until I read Raymond's paper.