"Artemis Tosini" <me@artem.ist> writes:
In many countries it is not possible (or is unclear if it is possible) to put a work into the public domain and grant all rights. Some licenses, such as CC0, are designed so that even if putting works into the public domain is invalid users will still have all rights afforded as if it were in the public domain.
However, given that all of the people who have historically submitted commentary or other patches that have been incorporated into tz did not agree to the CC0 license explicitly or implicitly (the license postdates much of this work), it's hard to see how anyone could reasonably claim that tz is under such a license. There is a large grey-area assumption with most free software packages that do not do either copyright assignment or CLAs that people contributing patches are doing so under the prevailing license of the thing to which they're contributing at the time and cannot reasonably object to their work being redistributed under that license. That license for tz has been stated for some time to be "public domain" and prior to that was left largely unstated. Despite all the issues with the "public domain" concept in international copyright law, I doubt claiming some other license now would be on any firmer legal ground. The practical reality is that it's highly unlikely that anyone is going to assert copyright rights over material in the tz distribution (to the extent that it's copyrightable at all, which is probably limited to the code and the commentary), and if they do, the details of the case seem likely to turn on elements other than the license statement. Lawyers may not be happy about the uncertainty and may want to transfer that uncertainty to some other party with some legal document. If I were Paul, I wouldn't want any part in that. There's essentially no upside for him as maintainer to accept any responsibility or liability for the uncertainty. If IANA wants to take on some of the legal uncertainty, well, at least have legal counsel to advise on the merits of and tactics for doing so. -- Russ Allbery (eagle@eyrie.org) <https://www.eyrie.org/~eagle/>