Second, changing the license is a permission granted only to the copyright owner. Otherwise I could take BSD-licensed code, relicense it to WTFPL, and then include it in my code without any credit to the original author.
Most licenses do not permit any sort of modification or version upgrade. The standard GPL boilerplate is extremely unusual for giving third parties a range of permitted versions.
> almost all non-GPL open source code can be relicensed as GPL.
This is absolutely wrong. You do not have the right to change the license of someone else's code.
For what it is worth, this is where this argument often ends up.
You can reason that developers are users if you can reason that software is a tool.
You can reason that developers are not users if you can reason that software is a product.
You can reason that developers are both users and not users if you can reason that software is an ingredient.
And that is where it gets tangled.
There is absolutely no incentive to build GPL software into products because of the covenants it requires.
There is little incentive to not use GPL tools because the covenants result in a lower cost for the tools if they are covered by the GPL.
The effect of this is that the majority of users of products which contain GPL'd software, are developers. [1]
[1] Or family members of developers, my Dad has a router with OpenWRT running on it but he could not have installed it, nor would the company that sold the router ever use OpenWRT as the supported firmware for the product.
Okay, so changing a license to GPL does not violate the conditions of the BSD. You just have to maintain the little notice and the copyright. If you want you can call it GPL+BSD but it's obviously identical to GPL.
Basically, you can convert the same code from BSD to LGPL to GPL to AGPL, but you cannot go in the other direction.
> Okay, so changing a license to GPL does not violate the
> conditions of the BSD.
Yes, it does. Just because code is under the BSD license doesn't put it in the public domain. I still need to comply with its terms, and I'm not allowed to change the terms of other people's code.
> You just have to maintain the little notice and the
> copyright.
In other words, I have to continue to comply with the terms of the BSD license.
> If you want you can call it GPL+BSD but it's
> obviously identical to GPL.
It's not identical to the GPL, because all of the terms of the BSD license remain in force. I have to give attribution, I have to include the text of the BSD license, and (for the 3-clause version) I can't use the identity of the BSD'd library authors to promote my own work.
When two works are combined, it is very important to know that their licenses are combined.
> Basically, you can convert the same code from BSD to
> LGPL to GPL to AGPL, but you cannot go in the other
> direction.
The LGPL -> GPL -> AGPL path exists because these licenses explicitly state that code they cover can be used under the terms of the "stricter" license.
> Are you disagreeing with the FSF's lawyers here?
You linked to a source which has nothing to do with your argument, which makes me think you don't really understand the position you're claiming.
If you say that it's legal to change the license of BSD-licensed code to GPL, that means you think it would be legal to:
1. Download the FreeBSD kernel.
2. Replace the LICENSE file with the GPL.
3. Replace the authorship and copyright comments with your own name.
4. Publish the resulting code online.
Do you really believe that doing that would be legal? If so, that is such an extremely unusual position that I do not know what evidence would be required to correct you.
I'm sure that one could contrive a GPL wrapper project to contain the BSD kernel. Nobody ever said anything about removing copyright notices or breaking license terms.
I agree that I could have been more precise. Again, I thought this was widely understood. I apologize for my lack of clarity. I was never suggesting some extra-legal method; it simply didn't occur to me because I would never consider this in a software licensing discussion.
When I say relicense a BSD project under the GPL, I mean take the existing codebase and go through whatever legal steps are necessary (without additional permission from the copyright owners) such that the resulting distribution can accept future contributions under the GPL.
So do you now understand what I mean, and see that it's possible with the right legal wrangling, per the link from the Software Freedom Law Center?
> Okay, so changing a license to GPL does not violate the conditions of the BSD. You just have to maintain the little notice and the copyright.
Not requiring this downstream violates the BSDL, but requiring it downstream, violates the GPL, at least in GPLv2, which does not itself require it, and prohibits additional terms to its own.
I think the GPLv3's allowance of additional terms is broad enough to actually make some of the licenses that the FSF promoted as GPL compatible under GPLv2 but which were clearly not on a reasonable reading of the terms of the licenses compatible with the GPLv3.
Second, changing the license is a permission granted only to the copyright owner. Otherwise I could take BSD-licensed code, relicense it to WTFPL, and then include it in my code without any credit to the original author.
Most licenses do not permit any sort of modification or version upgrade. The standard GPL boilerplate is extremely unusual for giving third parties a range of permitted versions.
This is absolutely wrong. You do not have the right to change the license of someone else's code.