What's already been said is good advice. At first, it may be a bit tricky to under copyright and licenses. When I started out, I for the longest held back on releasing software / packages because I somehow thought I basically had to make a final decision on the license at that moment and that the license was stuck forever. I was wrong. It will stick forever, but only per release.
Here is how *I* think of copyright and software licenses these days: * The copyright holder of a piece of software is the one who can decide on what license he or she would like to distribute that software. * If there are multiple copyright holders of your software, then all of you need to agree on the license. * If someone contributed a non-trivial part of code to your software, then that person holds copyright to that piece of code. From this point in time, your software has two copyright holders. * For you to remain the sole copyright holder, you need to make an explicit agreement with the other person that s/he transfer the copyright to you. Some maintainers (private person and / or companies) do this in order to keep full control of the decision on software licenses (for monetary and / or practical purposes). * When releasing a software under a specific license, then you give the users the rights specified in that license. * It is not possible to revoke licenses retroactively because then you would break the rights you have already given the users. If version 1.0 was released with license A, you cannot go back a say it now should be license B instead. * At any time, the copyright holder may choose to use a different license of a _future_ version of the software. Even if version 1.0 was released with license A, version 1.1 can be with license B (and license A can be dropped). * Software can be release with multiple licenses. You can choose to release version 1.1 under license A and license B. Then it is up to the user to choose which one s/he wish to follow / agree to. Moving from GPL 2 to GPL (>= 2) == GPL 2 | GPL 3 would be such an example. * If you're not the sole copyright holder, and you cannot agree with the others or you fail to get in touch with the others (e.g. person passed away), then the only way for you to become the sole copyright holder is to remove the parts of the code that you don't have copyright to. When the remaining code is truly yours, i.e. you are the sole copyright holder, then you have all the rights to choose license going forward. So, in your case, it is only people who have contributed to your piece of software ("foo") that can make copyright claims to it. Any software that depends on your software is completely irrelevant to this. If you're the only one who contributed to your package, then you can choose whatever licenses you want going forward (=next version). Also, the license of your software "foo" sets the rules for any software that depends on it, and not the other way around (unless you have a circular dependency, which is extremely rare). Hope this helps Henrik On Sun, Nov 6, 2016 at 9:10 AM, Dirk Eddelbuettel <e...@debian.org> wrote: > > On 6 November 2016 at 16:53, Lenth, Russell V wrote: > | Permission of "all other copyright holders" as in developers of all > packages that depend on 'foo'? > > Please do have a look at the two FAQs I referenced before: > > https://www.gnu.org/licenses/gpl-faq.en.html > > https://www.gnu.org/licenses/old-licenses/gpl-2.0-faq.en.html > > In particular this last question of yours is addressed in > > https://www.gnu.org/licenses/gpl-faq.html#HeardOtherLicense > > Dependent packages are of cause NOT the copyright holders. Rather, the > authors of a package (ie you, and whoever worked with you) are. > > Dirk > > -- > http://dirk.eddelbuettel.com | @eddelbuettel | e...@debian.org > > ______________________________________________ > R-package-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-package-devel ______________________________________________ R-package-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-package-devel