Re: License question.

Dear Stuart (?),

I know that there is a lot of uncertainty and misinformation on the meaning
of the GPL license terms. Hence, I always recommend to have a look at
the actual GPL license text and not just rely on what you can read in
license FAQs or on internet forums because the license text is the only
legally binding agreement.

You can read the GPL license text here:

http://cvs.xvid.org/cvs/viewvc.cgi/xvidcore/LICENSE?revision=1.3

So to answer your request: The question whether you link to xvid at all
or in which way exactly you link is irrelevant under the GPL. If you have
a look at the license text you'll realize that the word "linking" is not
used in the GPL at all.

The GPL requires you to license "derivative works" under the GPL again.
So the question that counts here is whether your distribution of xvid in
combination with your program will make up a derivative work or not.

The way how you currently handle the situation (so just referring your
users to the xvid homepage) is certainly fine because by this you are
not distributing xvid yourself.

Now when you intend to distribute xvid together with your proprietary
program this very likely makes up a derivative work even if you keep the
xvid installer as a separate file. That is because you bundle xvid with
your program for use in combination at runtime and xvid is shipped as a
part of your product. When buying your product people expect that they
paid for everything that's in the box and that all software included is
part of your product. So your package is distributed and perceived as
one product and hence a derivative work.

The mere aggregation exception only applies if the above is not the case,
so if there's no derivative work. An example could be software CDs that
are bundled with computer magazines. In this case people know that such
CDs are collections of useful programs and that a lot of different software
of different origin is just placed on the CD side by side.

I admit that the exact distinction between what is still a "mere
aggregation" and what is already a "derivative work" can sometimes be a
bit blurry. I advise however to avoid potential grey areas and go with a
solution that is clearly compliant. In your case: If referring your users
to the xvid homepage works well for you except for some users that are not
online - why not offer the few offliners to send them a separate disc
containing xvid upon request? If just few of your customers use xvid with
your program and even fewer are offline this should work out fine.

If you have further questions you can also write to me directly as this
discussion may probably not be interesting to everyone on the xvid-users
mailing list...

Best regards,
Michael



Quoting qzm <[email protected]>:

> Please forgive me for asking a question that is likely to stir up some
> disagreement, however I have been trying to track down an answer, or at
> least someone who can answer - perhaps here is a good place.
>
> The short version is that I am trying to clarify the restrictions on
> providing the xvid codec as a binary installer (not in any way modified,
> simply the current windows binary vfw codec linked from xvid.org) to some
> users of my own (non GPL) software.
>
> Now, that would of course be highly incorrect if my software required xvid
> use, however the situation I am in is that some clients have other third
> parties supplying them with xvid specific video files, and they complain to
> me if these files will not work in my software - I point them at the
> xvid.org site of course but not all situations are online computers - so
> they ask me to supply the installer. I would rather not tell them to avoid
> the files.
>
> My software simply uses VfW/Directshow to access the files - however that of
> course causes a loading of xvid for video that requires it (or a failure to
> load the file..). I guess technically it comes down to the question of does
> VfW/Directshow autoloading xvid constitute a linking or a seperate use - as
> OS services are in the middle here outside my control (I do not even
> know/care if the file requires xvid) I would err on the side of the second.
>
> Reading the xvid FAQ it seems very strongly to state this is not allowable,
> which does seem a touch surprising as by my understanding (and I know this
> is often debated..) the aggregation clause of the GPL would allow me to make
> the installer available alongside my application so long as my clients have
> the choice to install it (or not), and I in no way modify it, its licenses,
> or their presentation/function.
>
> However, I of course do not wish to cross any lines, and have great respect
> for the wishes of the xvid developers, so seek clarification.
>
> I would love to get in touch with the license holder of xvid to ask
> directly, however this is of course a difficult thing to achieve for any
> such project.
>
> Again, sorry if this is a poor place for this question, I would love to be
> able to track down a more official contact for such questions.
>
> http://www.xvid.org/FAQ.42.0.html#c44
> http://www.gnu.org/licenses/gpl-faq.html#MereAggregation
> http://forum.doom9.org/showthread.php?t=125721
>