Bradley Kuhn writes about the phrase "open core". In summary, avoid that phrase and use clearer, unambiguous terms instead.

He also touches upon the practice of projects requiring copyright assignment before accepting contributions. Like Bradley, I dislike the practice.

If a corporation requires me to assign copyright to them, so that they have power to change the license, I need to be paid in a currency that helps me pay rent. The only reason they need the power to change the license is to make the code proprietary, for the purpose of extorting users for money. If they get money, I want money.

On the other hand, if I don't assign them copyright, I have a bit of power myself, and I can use that to keep them honest. If enough people do that, the corporation would have to rewrite all the code to make sure they have copyright on all of it, and can license it in a proprietary way.

There's another kind of copyright assignment, which the FSF uses: the FSF gets copyright, but the contract with them guarantees that they'll not violate the freedom of the code. In return, the contributor gets relieved from the burden of having to deal with license violators, and can rely on the FSF to do that instead. This is an acceptable bargain to me, even though I haven't contributed enough to GNU projects to do a copyright assignment.

There may be other entities than the FSF doing the same thing. I have not seen any others, though, so on the whole I consider copyright assignment as a way to trick me. With the exception of the FSF, copyright assignment smells dishonest to me.

I feel a lot less bothered by joint copyright assignment (in which I also retain the copyright) than by copyright assignment in which I no longer hold any copyright.
Comment by JoshTriplett Sun Mar 6 09:59:45 2011

FSF claims they need the copyrights to pursue cases where third parties infringe on their copyrights. Which seems baloney to me, but if that's true, don't you think it would also apply to companies too?

So, if a company that is distributing its software under GPL doesn't require copyright assignment, if (per FSFs logic) that prevents them from pursuing a competitor which has taken their software and made it proprietary, wouldn't that be a good reason for requiring copyright assignment?

Personally I feel I would have to think twice even if FSF wanted me to make a copyright assignment. But that just might be an acceptable enough caes.

Comment by Sami Sun Mar 6 16:32:44 2011

It's clear by now, I think, that copyright assignment is not necessary for an entity like Canonical or the FSF to do copyright license enforcement. It may be necessary for the FSF to own at least some of the copyrights to be able to sue an infringer, but it's not necessary for them to own all of it.

The field of GPL enforcement has been reasonably active in the past several years to prove this, I think.

Comment by Lars Wirzenius Sun Mar 6 16:58:38 2011

I share Lars' feelings about why a company wants copyright transferring but still, there're some cases I'd want to do it. You can see it as offering your code to the company under BSD while still having it for next version as GPL on a global basis (the side effect is that you can get code from other people under the same conditions). So, if it's a minor enhacement that helps to scratch my own itch, I would probably offer even to a closed source company under BSD terms if only to avoid repatching and maintenance in future versions (and I'm in advantage here, since I probably couldn't do that on a "real" closed source program), I'd pass away non-exclusive copyright to them.

On a note to Sami, no, the company doesn't need your copyright for legal defense since yours will be one line among thousands: there's no way the company will need legal defense only for your tiny bit; they'll get that from the lines developed from themselves. See that's not the case for the FSF since they don't hire programs of their own (that I know of, correct me if I wrong) so all their code base comes from "everywhere else"; that's specially true for the case of transferring a whole program to them.

All in all, I feel the "deep" question is not about transferring copyright to a parent company or not, but for the project environment itself: there are to axis here: 1) About the license: closed or open, and open-ala-BSD or open-ala-GPL within open (copyright/copyleft). 2) About the project environment: community-based, company-controlled.

I think we must understand that just as closed source presents a different nature to open source (and copyright is different to copyleft within open source), community-based projects are different beasts to company-controlled ones and as such show different behaviour.

Comment by Jesús M. Sun Mar 6 21:54:26 2011

[Working through a Planet Debian backlog, hence the delayed comment.]

I largely agree with Lars's sentiments, but have mixed feelings about the FSF's insistence on holding copyright on GNU projects in their entirety, mainly because it lets them get away with copying examples, comments, and the like back and forth between GPL-licensed code and GFDL-licensed documentation, which doesn't even meet the DFSG if it uses cover texts or invariant sections.

Comment by Aaron Wed Mar 23 16:54:33 2011