[Qgis-user] gdal-ecw distribution / licensing

[Alister Hood]

(Oops, try again. Sorry Nathan for the second copy):

Sorry everyone,
Looks like I've messed up this thread a bit by hitting reply instead
of reply all, and
also sending one email accidentally.  I'll try to reassemble it, since
I wanted to get
the logic on the record:

On 21/08/2013, Nathan Woodrow <madmanwoo at gmail.com> wrote:
>On 21/08/2013, Alister Hood <alister.hood at gmail.com> wrote:
>> On 21/08/2013, Nathan Woodrow <madmanwoo at gmail.com> wrote:
>>> This is not a QGIS GPL thing. It's related to GDAL.
>>
>> That'd be find if you were just shipping it with gdal.  e.g. you could
>> ship it in an installer for an LGPL or proprietary licensed program
>> (e.g. an ECW header editor), and if someone wanted to they could
>> install that over the top of the gdal in a QGIS install.
>>
>> But if you're shipping it and gdal with QGIS, not as a separate
>> program, then the QGIS license is also relevant.  Isn't this situation
>> the exact reason why the LGPL is mentioned in exceptions like this?:
>> "In addition, as a special exception, the copyright holders of ABC
>> give you permission to combine ABC program with free software programs
>> or libraries that are released under the GNU LGPL and with..."
>> (http://www.gnu.org/licenses/old-licenses/gpl-2.0-faq.html#GPLIncompatibleLibs)
>>
>> Or is it somehow different in this case because the interface with the
>> ECW libs will be separated out into a separate gdal-ecw "plugin", and
>> QGIS and the main gdal lib can function fine without that?.
>
> I'm pretty sure this is the case.  Some that want to follow GPL to the letter
> might not see it as still workable but most see it as fine.  It's the same if I
> complied GDAL with DWG support because it needs a propitiatory driver.
> QGIS will work with it fine, but in that case we can't ship it because we can't
> ship the closed DWG drivers.
>
>>> gdal-ecw is built
>>> against the ecw libs and we just have to ship them with QGIS so GDAL can
>>> find them.  The GDAL licence allows this and Intergraph allows you to
>>> ship
>>> the ECW read-only libs as long as you show their EULA for them in your
>>> application.  For us this will be shown on install and in the about
>>> dialog.
>>>
>>> - Nathan
>>>
>>>
>>> On Wed, Aug 21, 2013 at 11:54 AM, Alister <alister.hood at gmail.com> wrote:
>>>
>>>> Hi guys,
>>>> I've never understood why we had a concern about licensing on the
>>>> Intergraph side in the first place.  But has anyone recorded the logic
>>>> around how this doesn't violate *the GPL*?  Wouldn't QGIS need a license
>>>> exception to allow this?  If not, it would be nice to put this
>>>> interpretation of the GPL on the record...
>>>>
>>>> Regards,
>>>> Alister

The punchline is in the middle with Nathan's example of ECW vs DWG, except it's
a little unclear - I think he's saying that DWG support is built into
the main gdal lib,
not as a plugin, so he really means it's _different_ with DWG, not _the same_.

FWIW, because of the exception clauses I referred to and
interpretations like at
http://gstreamer.freedesktop.org/data/doc/gstreamer/head/faq/html/chapter-legal.html
I still haven't seen enough to convince me that this reasoning is correct.
If anyone has a good reference supporting it that'd be great, but at least now
the reasoning is clear.