Hi zimoun zimoun writes: [...] > Where is the License of Perl 5 and below explicitly defined? There is > no pointer... Ricardo pointed you to https://dev.perl.org/licenses/, that is a web version of this https://perl5.git.perl.org/perl5.git/blob/HEAD:/README Perl is dual licensed at least since 1994-10-17 (see the README history [1] > What I understand is: when the License of Perl 5 There is no "License of Perl 5", it is Perl 5 that is dual licensed The same dual license scheme is usually (usually?!?) adopted by Perl modules, at least those on CPAN http://www.cpan.org/misc/cpan-faq.html#How_is_Perl_licensed > and below is used, then the copyright holder chooses either the > Artistic 1.0, either the GPL. Then the License of Perl 5 and below is > free but non-copyleft. Since there is no "License of Perl 5" that license cannot be qualified :-) > Well, it appears to me a hack. I guess that there is a lot of Perl > packages under Artistic 1.0 which seems an issue. I don't know how many packages/modules are distributed only using Artistic License 1.0, but please consider that as I said above that *many* are dual licensed. The fact that Perl modules are (must?) commonly dual licensed is somewhat a mystery to me, but I do not care :-D > So let create this License of Perl 5 and below saying: choose between > Artistic 1.0 or GPL. And because you have this choice, everything is > fine. > > I probably misread No, you do not misread: dual licensing is used in many situation and is non a "hack", it's the decision of the copyright holder to allow different legal uses of the software In this particular case, **fortunately** the dual licensing was adopted "since the beginning" to fix the problems with Artistic License [...] Last things about names: since Oct 2019 [2] Perl 5 is Perl (Perl 4 is gone long ago) and Perl 6 is Raku, so finally there is no more need to say "Perl 5" :-) Ciao! Gio' [1] https://perl5.git.perl.org/perl5.git/history/HEAD:/README [2] https://lwn.net/Articles/802329/ -- Giovanni Biscuolo Xelera IT Infrastructures