[pdf-devel] Re: about the licence

[Yavor Doganov]

Brad Hards wrote: 
> I'm not aware of any part of poppler that is not "GPL version 2 or
> later". Can you point to a "v2 only" part that is actually linked
> into the library?

Poppler is a fork of xpdf, which is GPLv2 only (I'm sure you know
that).  As such, it cannot be released under GPLv3 unless all xpdf
code is rewritten.  Of course, the poppler developers (yourself
included) can release their code under GPLv2+, but this only means
that someone can reuse *that specific code* under GPLv2+ -- i.e. it is
not possible to link a GPLv3 app against poppler, and it is not
possible to link a GPLv2+ app against poppler *and* a library under
LGPLv3.

Some consequences of this are well known -- for example, GLib/GTK+
can't migrate to LGPLv3+ because that would rule out Evince (since it
links against poppler), libgoffice->Gnumeric, etc, and probably lots
of other applications that are important for the GNOME desktop (and
maybe Xfce/LXDE too).

The GNUstep librararies were released under LGPLv3, and subsequently
downgraded to LGPLv2.1 because Vindaloo.app links with poppler (via
PopplerKit), the GWorkspace PDF Inspector does that too, Terminal.app
has some Linux code, etc., etc.

Poppler is a major technical obstacle towards the adoption of (L)GPLv3
(by "technical" I mean when the copyright holders wish to use the new
licenses, but they cannot for compatibility issues because of the
libraries they use).  I'd wish it was the only one, but it's not.