CGAL users discussion list

[Patric Schmitz <>]

Hello Maria, [Hi list!]

Disclaimer: I'm answering to the best of my knowledge and I am
not part of the CGAL development team.

On 02/10/2016 05:00 PM, Maria Dubrovskaya wrote:
> I would like to use some CGAL features licenced under LGPL in my
> commercial program, without modifying them.
> I wouldn't like to open my own code, so I have several related
> questions.
> 
> 1. Will I have to open any code in this case?

If you just link against the library or derive classes from
public headers, using an LGPL library does not impose any
licensing restrictions on your own code, as opposed to the GPL.

Taking parts of the source code and incorporating them somehow
into your own code, thus building a 'modified version' or a 'work
based on' the LGPL-covered software *will* require you to impose
the same or a compatible license on the resulting work.

> 2. Will I have to do any additional actions, e.g. support the
> last features' versions usage by my program or anything else? If
> yes, could you show me the whole list of those?

I don't exactly get that point, but the LGPL does not enforce you
to support or make use of a particular version of the covered
software.

> 3. Will I have to open my code for my either current or future
> customers if any feature's LGPL licence is changed to GPL?

Only if you want to make use of that hypothetical newer version
(or the parts) which would only be covered by the GPL. If you
stick with the version which you received under terms of the
LGPL, relicensing the library in any form will not affect the
licensing terms you are bound to.

> 4. Am I allowed to link the library statically?

Yes you are. Regarding this, see:
> http://www.gnu.org/licenses/gpl-faq.html#LGPLStaticVsDynamic

Saying that if you link statically against an LGPL library, you
must provide the object files (not source code) of your
application, so the user is able to relink your application with
a different version of the library.

Reading that whole GPL FAQ might be helpful either way to sort
any any questions you have about the GPL/LGPL relation.

Best,
Patric Schmitz