[gdal-dev] Click through proprietary licensing

Even Rouault even.rouault at mines-paris.org
Thu Nov 11 18:15:08 EST 2010

Le jeudi 11 novembre 2010 19:55:27, Frank Warmerdam a écrit :

Yes, this is a tricky situation. 

In fact, the potential legal infringement doesn't come necessary only from the 
side of the proprietary software. Even if you satisfy the licencing terms of 
the former, the copyright holders of the GPL software could argue that the GPL 
licence doesn't apply in that context.

The issue is not using GPL and proprietary stuff, but distributing the 
aggregation of the two. Whether the fact of distributing a GPL program 
(QGIS/GRASS/...) that uses a X/MIT library (GDAL/OGR) that has a X/MIT plugin 
(OCI driver, ECW driver, MRSID driver) that links to a proprietary plugin (OCI 
library, ECW library, MRSID library, ...) is illegal or not is probably in the 
gray area of the GPL ( there is always debate on how linking and GPL work : 

A few points to consider :
1) The proprietary libraries cannot reasonnably be considered as a derivative 
work of QGIS/GRASS. And the GPL only covers the '''Program or a "work based on 
the Program" means either the Program or any derivative work under copyright 
law''' according to article 0 of the GPLv2.
2) GDAL wasn't designed in the sole purpose of being a wrapper to make it 
possible to use proprietary plugins from GPL software
3) I'm not even sure that http://www.gnu.org/licenses/gpl-
faq.html#GPLAndPlugins which seems to be the closest entry of the FAQ covering 
the situation really applies. AFAIK, they don't "make function calls to each 
other and share data structures"
4) And the last sentence of clause 2 of GPLv2 could perhaps apply to OSGeo4W 
situation : "In addition, mere aggregation of another work not based on the 
Program with the Program (or with a work based on the Program) on a volume of 
a storage or distribution medium does not bring the other work under the scope 
of this License. ".

So we could probably say that those proprietary plugins are out of the scope 
of the GPL licence, but I'm not 100% this is a valid interpretation...

Of course, there are some possible ways to solve this without ambiguity :
a) either those proprietary stuff are licenced under a GPL compatible open-
source licence... (well one can dream...)
b) or the copyright holders of those GPL software agree to provide a special 
exception clause to the GPL to allow it to be combined with proprietary 
software. Not necessarily easy in the presence of multiple copyright holders.

As far as MapServer and its potential use of proprietary software, it's a 
completely different story since the X/MIT licence doesn't impose any 
restriction on the combination of it with other work.

> Folks,
> We have come to the conclusion that we can't really distribute the OCI
> (oracle client interface) libraries as an OSGeo4W package without forcing
> people to agree to a click through license first.
> Howard and I were discussing the possibility of implementing a mechanism
> in the OSGeo4W package manager to present custom license text for a package
> and force the user to decide if they are willing to comply with it before
> a package is installed.
> There are some technical challenges to making this work, but I'm really
> writing today to ask this community how it feels about inclusion of
> proprietary software in OSGeo4W and putting click-through licenses in front
> of people.
> I personally have a few concerns.
> 1) It pisses me off to feel I'm having to bend over backwards to help
> proprietary software vendors assert their rights over OSGeo4W users.
> 2) We really ought to become more aware of the implications of mixing
> proprietary software and GPLed software in OSGeo4W.  For instance, it is
> not legal for us to distribute proprietary software that would be used
> by a GPLed package like GRASS.  In fact we are likely already in violation
> of this when GRASS uses the MrSID driver (though Lizardtech bent over
> backwards to make sure we didn't have to put our users through a click
> through license for it).
> On the other hand, OSGeo has taken the position of building bridges between
> proprietary and free software.  In particular of being supportive of things
> like being able to use MapServer against proprietary databases, supporting
> proprietary file formats and such.  So I don't feel that including such
> bridges in our distributed packages is unreasonable.
> Also, I am keen to provide the best user experience I reasonably can for
> OSGeo4W users and being able to include some proprietary components could
> certainly go a long way to making that work (ie. ECW SDK, OCI, ...)
> So, anyone else have a strong opinion on the matter?
> Best regards,

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