Dear Mark,
I heard back from the licens...@fsf.org.
1.
Importing the GNUBG Python package directly into proprietary code
*
Because the GNUBG C-extension is licensed under the GNU GPL, any software that
links against it (i.e. imports it as a library) becomes a “derived work” under
the GPL.
*
The GPL explicitly states that “you cannot incorporate GPL-covered software in
a proprietary system” – if you distribute the combined work, you must release
the entire work under the GPL and provide full source code for everything that
links to it
(gnu.org<https://www.gnu.org/licenses/old-licenses/gpl-2.0-faq.html?utm_source=chatgpt.com>).
2.
Calling GNUBG as an external service
*
If you run the GPL-licensed code in a separate process or server and your
proprietary application communicates with it over, say, a REST API or
command-line interface, then they remain two independent programs.
*
In that case, you’re not “linking” them into one program but rather
distributing them side by side, which the GPL permits provided they communicate
“at arm’s length” and aren’t effectively a single work
(gnu.org<https://www.gnu.org/licenses/old-licenses/gpl-2.0-faq.html?utm_source=chatgpt.com>).
________________________________
Relevant links
*
GPL FAQ on proprietary systems:
https://www.gnu.org/licenses/gpl-faq.en.html#GPLInProprietarySystem
*
Why we say “free software” rather than “open source”:
https://www.gnu.org/philosophy/open-source-misses-the-point.en.html
*
On the meaning of “commercial” vs. “proprietary”:
https://www.gnu.org/philosophy/words-to-avoid.en.html#Commercial
*
Selling free software:
https://www.gnu.org/philosophy/selling.en.html
Hope that clarifies things!
Best,
David
________________________________
From: Mark Higgins <migg...@gmail.com>
Sent: Wednesday, June 4, 2025 4:09 PM
To: DAVID REAY <dr323...@falmouth.ac.uk>
Cc: bug-gnubg <bug-gnubg@gnu.org>
Subject: Re: Alpha Release of Python3 Extension Module
CAUTION: This email originated from outside of the organisation. Do not click
links or open attachments unless you recognise the sender and know the content
is safe.
This looks exciting!
From an open source license perspective - if I import this Python package into
my commercial Python software, does that force me to open source my software?
I’m confident I do not have to do that if I call gnubg as an external service.
On May 25, 2025, at 1:43 AM, DAVID REAY <dr323...@falmouth.ac.uk> wrote:
Dear GNU Backgammon Developers,
I'm writing to share the alpha release of the Python extension module that
wraps the GNU Backgammon neural network evaluation engine.
It is now available on PyPI:
📦 PyPI: https://pypi.org/project/gnubg/
📖 Documentation: https://gnubg.readthedocs.io/en/latest/
I’ve taken care to attribute Joseph Heled and the original authors in the
source and license:
*
AUTHORS file:
https://github.com/reayd-falmouth/gnubg-nn-pypi/blob/main/AUTHORS.md
*
Copyright notice:
https://github.com/reayd-falmouth/gnubg-nn-pypi/blob/84b814f9b9152526bdead640770643f2600fad75/src/gnubg/gnubgmodule.cpp#L1-L23
Due to persistent HTTP 500 errors on Savannah, I created a GitHub mirror of the
gnubg-nn repo here for stability and accessibility:
🔗 https://github.com/reayd-falmouth/gnubg-nn
I hope that’s OK, but please let me know if there are any licensing or hosting
concerns.
I’d be very grateful for any feedback, bug reports, or suggestions to improve
the extension, documentation, or packaging.
Best regards,
David
David Reay
📧 dr323...@falmouth.ac.uk<mailto:dr323...@falmouth.ac.uk>
🔗 itch.io<https://reayd-falmouth.itch.io/>
