[Qgis-developer] What's your view on QGIS plugins that connect to non-GPL software?

[Crispin Cooper]

Hi Vincent, thank you for your reply.

The QGIS plugin would not be essential to the external process as sDNA works on its own anyway.  The external process would however be essential to the QGIS plugin.

Is there any sort of official position on this, e.g. from the steering committee?

Best regards

Crispin

-----Original Message-----
From: Vincent Picavet (ml) [mailto:vincent.ml at oslandia.com] 
Sent: 08 September 2015 14:13
To: Crispin Cooper <CooperCH at cardiff.ac.uk>; qgis-developer at lists.osgeo.org
Subject: Re: [Qgis-developer] What's your view on QGIS plugins that connect to non-GPL software?

Hello Crispin,

On 08/09/2015 14:10, Crispin Cooper wrote:
> Hi qgis-developers,
> I produce my own network analysis software sDNA 
> (www.cardiff.ac.uk/sdna <http://www.cardiff.ac.uk/sdna>).  It 
> currently runs as a plugin for ArcGIS or Autocad, from the command 
> line, with a standalone GUI, or through a Python API.
> We would like to create a QGIS plugin that allows people to use sDNA 
> from inside QGIS.  sDNA is free but not open source, still I believe 
> this can be done within the terms of the GPL by running sDNA in a 
> separate process with pipe or file communication.  That said, I'd like 
> to know whether a plugin that loosely connects to proprietary software 
> would be welcome in the first place.

Some (almost 100%) sure things :
* a Python "import" means GPL "contamination"
* Calling an external process communicating through pipe or file does not imply GPL contamination

I would say that it is safe to have a qgis plugin calling a proprietary external process.
That said, I also think that your external process should not be a necessary part to run your software, otherwise it may be considered as a strong connection or inclusion, and be subject to GPL contamination. If it is optional, no problem. This specific point has to be verified though, not 100% sure.

Vincent
> 
>  
> 
> What are your thoughts?
> 
>  
> 
> Best regards
> 
>  
> 
> Crispin
> 
>  
> 
> --
> 
> Dr Crispin Cooper
> 
> Sustainable Places Research Institute, Cardiff University
> 
> 33 Park Place, Cardiff CF10 3BA
> 
> Tel. +44 (0) 29 2087 6072 / ext. 76072
> 
>  
> 
> 
> 
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