On Mon, 9 Jan 2012 00:17:39 +0100 chrysn wrote: [...] > On Sun, Jan 08, 2012 at 10:22:39PM +0100, Francesco Poli wrote: > > Have you tried to persuade libcgal copyright holder(s) to re-license > > libcgal under the GNU GPL v2 or later, or under the GNU LGPL v2.1, or, > > at least, to dual-license it under the QPL and one GPLv2-compatible > > license? > > i've checked the licensing situation and there have alreay been > approaches to convince them. the problem is, cgal is composed of > different modules by many different people, some of which are already > dfsg free, but others insist on sticking to qpl. asking them one at a > time with a particular problem at hand (like i try here) is probably the > best i can do.
I think the best thing you could do is really trying to persuade CGAL copyright holders to re-license or dual-license under GPLv2-compatible terms. This strategy, if successful, would eliminate any necessity to add linking exceptions to other GPL-licensed works that link with CGAL, and a lot of people would be much happier. > > > > > As a special exception, you have permission to link this program > > > with the CGAL library and distribute executables, as long as you > > > follow the requirements of the GNU GPL in regard to all of the > > > software in the executable aside from CGAL. > > > > This CGAL-linking exception seems to be a bit incomplete. > > Shouldn't there be also the permission to drop the exception? > > Please see the phrasing recommended by the FSF for the GPL v2 + linking > > exception: > > http://www.gnu.org/licenses/gpl-faq.html#GPLIncompatibleLibs > > the wording follows exactly the wording recommended for a qpl exception > by the fsf[1]. This is awkward, I hadn't noticed that recommendation. It looks like the FSF is giving inconsistent advice on different FAQs... :-/ Maybe someone should point out this inconsistency to the FSF, so that it may be fixed. > the note on dropping it seems to be a good idea in case > some new library needs an exception, I would say that it is useful in case the linking exception becomes unneeded in the future, and, above all, it is important to let the GPL + linking exception combination stay GPL-compatible... > > > thanks for your input You're welcome! > chrysn > > [1] http://www.gnu.org/licenses/license-list.en.html#QPL -- http://www.inventati.org/frx/frx-gpg-key-transition-2010.txt New GnuPG key, see the transition document! ..................................................... Francesco Poli . GnuPG key fpr == CA01 1147 9CD2 EFDF FB82 3925 3E1C 27E1 1F69 BFFE
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