CGAL users discussion list

[Andreas Fabri <>]

Thanks Joachim.  In fact I only had the scenario of a
non open source software in mind. Even this one must
allow to replace the LGPLed part.

Obviously, if the source code of the higher level code (library
or application) is available the user of the LGPLed library
CAN replace this particular library with whatever alternative
version, and the goal of the LGPL is achieved.

best regards,

andreas

On 19/06/2011 17:00, Joachim Reichel wrote:
> Hi,
>
> On 06/17/2011 07:17 AM, Andreas Fabri wrote:
> > On 16/06/2011 22:05, Hamid G wrote:
> > > Hi
> > >
> > > I was wondering if you guys could also provide static gmp libraries with
> > > CGAL's Windows installer.
> > > Right now, libgmp.lib is an import library that calls libgmp.dll so I
> > > can not create a truly standalone executable application.
> > >
> > > As a side question, is it possible to combine an import library with its
> > > .dll so when I link my code against it, I get a full static executable
> > > that doesn't need a separate .dll to be shipped with it.
> > >
> > > thanks in advance,
> >
> > Hamid,
> >
> > GMP is distriuted under the LGPL, and it must be a dll according
> > to this open source license.
>
> sorry, that's not true. Many Linux distributions distribute static libraries
> under LGPL (and works derived from those static libraries, for debugging
> purposes). Looking at the LGPL v2.1 there are the following options:
>
> - the "executable that is a derivative of the Library" is covered under the 
> LGPL
> again (clause 5)
>
> - distribute the "work that uses the Library as object code and/or source 
> code"
> [so that the user can modify the Library and then relink to produce a modified
> executable containing the modified Library.] (clause 6a/d)
>
> - "use a suitable shared library mechanism for linking with the Library" 
> (clause
> 6b) (that's what you meant)
>
> (Clauses 6a and 6b also require permission of "modification of the work for 
> the
> customer's own use and reverse engineering for debugging such modifications".)
>
> The 2nd option is a bit impractical, but the 1st one is used quite often.
>
> > I would like to remind you that CGAL is also distributed under an
> > open source license, which is even stronger than the LGPL:  If
> > you distribute binaries you also have to distribute the source
> > code of your application as open source software.  Otherwise,
> > you need a commercial license for the CGAL components you use.
>
> That statement holds only true if the parts licensed under the QPL are used.
> Otherwise, the 3 choices above apply again (CGAL takes the place of GMP).
>
> Joachim


--
Andreas Fabri, PhD
Chief Officer, GeometryFactory
Editor, The CGAL Project

phone: +33.492.954.912    skype: andreas.fabri