[Qgis-developer] Plugin licence

[Even Rouault]

Le mercredi 25 mai 2016 13:26:02, Vincent Picavet (ml) a écrit :
> Hi,
> 
> On 25/05/2016 12:39, Even Rouault wrote:
> [..]
> 
> > <my ow opinion, not pretending this is the project one>
> > 
> > Technically you could licence the plugin with any license you want, but
> > as soon you execute it against QGIS, it must be compatible of GPL v2+,
> > since it is a derived work of QGIS GPLv2 code, and thus it must convey
> > the same rights and obligations offered and constrained by the GPLv2
> > license.
> > So you could also licence it under X/MIT, BSD 2/3 clauses or which ever
> > other free licences that are compatible with GPLv2+.
> > It cannot be under a proprietary license, because GPLv2 would impose to
> > have access to the source code.
> > 
> > The only cases where it makes sense in practice to have a plugin under a
> > permissive license are :
> > - imagine that someone would reimplement a QGIS alternative that would
> > have the same API as QGIS but would be more permissively licensed, then
> > it could make sense to have your plugin under that permissive license.
> > - a more reasonable use case would be a plugin that would be compatible
> > of QGIS and another proprietary GIS through some abstraction layer of
> > their different APIs. The core of your plugin could then be permissively
> > licensed to be compatible of both licensing models.
> > 
> > </my ow opinion, not pretending this is the project one>
> 
> I do agree with this analysis.
> 
> Note that as for the Nvidia case mentionned, the Linux kernel has an
> exception to GPL for proprietary modules. Not sure it plays a role on
> the issue you mentionned, but it may be a strong difference with other
> software which do not have this exception.

Are you really sure of that ? If that was the case there would not be all 
those debates regarding whether proprietary kernel modules are allowed or not.

My understanding of 
https://en.wikipedia.org/wiki/Linux_kernel#Loadable_kernel_modules is that all 
the subtelty resides in whether a module is a derived work of another one. 
There's no special explicit exception. The folks that put proprietary modules 
say they are not derived works from the kernel, hence not bound to GPL.

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