Re: FLTK License

[Olive <not0read0765@yopmail.com>]

On Tue, 24 Mar 2009 18:56:51 +0000
MJ Ray <mjr@phonecoop.coop> wrote:

> Olive <not0read0765@yopmail.com> wrote:
> > If I understand it well; the amendments of the LGPL are not
> > removable (it is not explicitly said to be removable so by default
> > it is not). But It seems then that this license might in fact be
> > incompatible with the LPGL.
> 
> They appear to be additional permissions, so are GPL-compatible IMO.
> 
> > In particular it prevents to relicence FLTK under the pure GPL
> > which is normally allowed by the LGPL.
> 
> Rather, it would be under the GPL plus additional permissions.
> 
> > Any derivative works of FLTK have
> > to be distributed with the additional permissions and that [...]
> 
> I don't see why authors of derived works have to grant the additional
> permissions.  Where is that requirement?

To distribute derivative works you need a license (otherwise it is a
copyright infringement). The way it is presented is not you have all
the right from the LGPL + additional permission but the license is the
following FLTK license which consists of a modified LGPL license. The
additional permissions make part of the license. 

Any derivative work is covered by the FLTK license and that include the
additional permissions. It is my understanding that you cannot change
the license at all unless it is explicitly permitted and I do not find
this permission (I think this is the reason that when the FSF give
extra permission, as it sometimes do, it clearly states you can remove
the extra permission; otherwise the same problem would occurs).

Moreover the LGPL sates:

[ For example, if you distribute copies of the library, whether gratis
or for a fee, you must give the recipients all the rights that we gave
you ]

This clearly suggests you must give the extra permissions to derivative
works.


Olive