I am willing to "give away" my software, so you might ask, "why license it at all?". In a perfect world there would be no reason to. What can happen without a license is that someone else can take your work, slap their own license on it, and then (especially if they have money) send their lawyers after me. Indeed, I am told that such things happen.
Apart from this, I am an enthusiastic supporter of free software. Yes, I know it is called "open source" these days, but I am an old timer. I believe the world is a better place when information and ideas are shared rather than hoarded. If someone else wants to keep their software private and make money doing they, that is certainly up to them. Each person is free to choose any license that they want.
Any discussion of this rapidly gets into the world of legal issues and intellectual property law. A couple of things are worth bearing in mind. First, the law is not about logic and in some sense not really about right and wrong. The law is about what laws are on the books and even more importantly about what court decisions have already been made on a given issue. This business of leaning on prior decisions is what is called "stare decisis". A cynical viewpoint is that it is a conspiracy among lawyers to avoid ever contradicting one another. The main point here is that the legal world is almost certainly not how and what you think it is.
“good artists borrow, great artists steal”GPL and open source is all about just this. Why recreate the wheel? Just maintain licenses and proper attribution and dive in. Copying without attribution however, is just plain old plagarism.
If you intend to publish books, apparently other issues can arise, but I am not an intellectual property lawyer, so you will have to look into these details yourself if this affects you.
I think this is a great quote. Apparently Steve Jobs of Apple Computer admired it also, or used to, then went on to aggressively confront anyone perceived of stealing ideas from Apple computer. A fascinating story, but one that drifts off the current topic.
You would be well served to read or listen to what Linus Torvalds has to say about all of this. If nothing else, Mr. Torvalds is an outspoken individual and a lot of fun to listen to. I find that I agree with virtually all of his conclusions, but your mileage may vary.
The GPL v3 seems to have been crafted to address the issue of "tivoization". In summary, Tivo hardware runs software licensed under the GPL v2, but uses digital signatures to prevent you from modifying the software. The FSF thinks this is wrong and has crafted the GPL v3 to prevent this. The accusation is made that the FSF has been sneaky about this, though I doubt if any alert lawyers have been fooled. Torvalds does not mind at all, all he wants is an exchange of ideas and to receive back any additions or improvements.
If you believe the statistics in the first article, the most popular license for new projects these days is the MIT license. I can't help but wonder if the issues raised by the GPL v3 are at the root of this trend.
Kyu / email@example.com