[Bf-committers] GPL + Python, revisited

Campbell Barton ideasman42 at gmail.com
Tue Mar 31 15:33:42 CEST 2009


Suggested change, mostly to the start
______________________
* Licensing Blender Python scripts


Scripts that make calls to the Blender Python API are exempt from the
usual restrictions the GPL applies in these cases.

This exception to the GPL allows you to run and re-distribute the
script in any way you like,
and there are no requirements about licensing that script to anyone.

The Blender Python Scripting API is defined here:
http://www.blender.org/documentation/248PythonDoc/index.html

This exception is only valid if the script doesn't use "bindings" (calls to)
to other libraries or facilities that are GPL licensed.

The GNU GPL defines that combining GPL licensed software (like
libraries, static or dynamic) via an interpreted script, effectively
will make the script GPL-compatible too.

http://www.gnu.org/licenses/gpl-faq.html#IfInterpreterIsGPL

In the case of linking a Blender Python script to modules, libraries,
plug-ins or programs that are not compatible with the GPL license, the
GPL license defines they form a single program, and that the terms of
the GPL must be followed for all components when this case gets
distributed.

* Licensing Blender .blend files

The output of Blender, in the form or .blend files, is considered
program output, and the sole copyright of the user. The .blend file
format only stores data definitions.
In case you embed the .blend file with Python scripts, and the scripts
provide bindings to other libraries or facilities, the above topic
applies.

* Disclaimer

The above statements are not yet officially confirmed by the Free
Software Foundation. In case the FSF concludes there's a conflicting
situation with the GNU GPL, the Blender Foundation will seek efforts to
include an amendment in Blender's GNU GPL license to secure this, based
on permission from all contributors, and relying on BF's compilation
copyright.



On Tue, Mar 31, 2009 at 6:07 AM, Ton Roosendaal <ton at blender.org> wrote:
> Hi,
>
> Still not much news from FSF on the topic, apparently it's not simple
> for them either.
> I proposed to them (and to this list now) to make the following
> official FAQ statement on the Blender Python license;
>
> (Explanation follows, scroll down)
>
> ----------------
>
> * Licensing Blender Python scripts
>
> When a script uses calls that are part of the Blender Python Script
> Language, the interpreted program, to the interpreter, is just data;
> you can run it any way you like, and there are no requirements about
> licensing that data to anyone.
>
> The Blender Python Script Language is defined here:
> http://www.blender.org/documentation/248PythonDoc/index.html
>
> This is true only and if the script doesn't use "bindings" (calls to)
> to other libraries or facilities that are GPL licensed.
>
> The GNU GPL defines that combining GPL licensed software (like
> libraries, static or dynamic) via an interpreted script, effectively
> will make the script GPL-compatible too.
>
> http://www.gnu.org/licenses/gpl-faq.html#IfInterpreterIsGPL
>
> In case you link a Blender Python script to modules, libraries,
> plug-ins or programs that are not compatible with the GPL license, the
> GPL license defines they form a single program, and that the terms of
> the GPL must be followed for all components when this case gets
> distributed.
>
> * Licensing Blender .blend files
>
> The output of Blender, in the form or .blend files, is considered
> program output, and the sole copyright of the user. The .blend file
> format only stores data definitions.
> In case you embed the .blend file with Python scripts, and the scripts
> provide bindings to other libraries or facilities, the above topic
> applies.
>
> * Disclaimer
>
> The above statements are not yet officially confirmed by the Free
> Software Foundation. In case the FSF concludes there's a conflicting
> situation with the GNU GPL, the Blender Foundation will seek efforts to
> include an amendment in Blender's GNU GPL license to secure this, based
> on permission from all contributors, and relying on BF's compilation
> copyright.
>
> -----------------
>
> Note: Once 2.5 is out, we can also limit a license amendment to the 2.5
> Python API, making it less complicated to get the contributors to agree
> on it.
>
> The basic thought behind this proposal is to ensure that all artistic
> output that's stored in a .blend file, remains the sole property of its
> creator. Python constraints, logic scripts, procedural objects, custom
> editors or exporters included.
>
> However, if you extend Blender - via Python - to link to other programs
> or libraries, you have to follow the letter of GPL still. This
> extension simply occurs when your code doesn't run anymore in the
> Blender script interpretor.
>
> What this would enable is for example:
>
> - Companies posting exporters or importers under own copyright and
> license conditions.
> - Studios creating a Blender configured level editor, with proprietary
> file exporting, and limit distribution of these scripts or .blends to
> own relations only.
>
> What is *not* possible then:
>
> - Offering the Blender binary with own scripts under a single closed
> license.
> - Combining the Blender Player with a .blend file, under own license.
> - Or in general, limit distribution or usage of Blender in any way
> other than GPL. :)
>
>
> -Ton-
>
> ------------------------------------------------------------------------
> Ton Roosendaal  Blender Foundation   ton at blender.org    www.blender.org
> Blender Institute BV  Entrepotdok 57A  1018AD Amsterdam The Netherlands
>
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> Bf-committers at blender.org
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>



-- 
- Campbell


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