[QGIS-Developer] Plugin licensing requirements

[Nyall Dawson]

On Thu, 7 Jan 2021 at 19:13, Topi Tjukanov <topi at gispo.fi> wrote:
>
> Howdy list,
>
> One question that keeps popping up with QGIS plugin development is one regarding the licensing requirements. As per my understanding the plugins have to be GPL compatible (GPL2 or higher) and that is what these resources also suggest:
> https://blog.qgis.org/2016/05/29/licensing-requirements-for-qgis-plugins/
> https://gis.stackexchange.com/questions/61065/qgis-plugin-licence

>
> If that is the requirement, why plugins are accepted to the official repository with various licenses and the requirement is not enforced in any way?
> For example here are a few I found quickly with a random check:
>
> MIT license: https://plugins.qgis.org/plugins/XYZHubConnector/
> MIT license: https://github.com/gee-community/qgis-earthengine-plugin


> No license: https://github.com/riccardoklinger/amaps

This one is fine -- it just uses license headers, eg
https://github.com/riccardoklinger/amaps/blob/master/amaps.py#L15

> So if this really is a requirement, should this be enforced somehow and checked when plugins are accepted to the official repository?

Agreed, but keep in mind that it's a little tricky sometimes. A plugin
ONLY has to make the modules which import QGIS classes GPL (and
consequently any other modules which import these modules). It is
entirely possible to separate plugins into two isolated components, a
non-GPL "core" layer which does NOT use any QGIS modules, and a GPL
layer which imports both the QGIS modules and the non-gpl core. (This
is how the licensed SLYR plugin works, for reference).

So to enforce this in some circumstances you'd need to check
file-by-file, which is going to be time-consuming.

Nyall


>
> Kind regards,
> Topi Tjukanov
> Gispo Oy
> _______________________________________________
> QGIS-Developer mailing list
> QGIS-Developer at lists.osgeo.org
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer