[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: question about gpl-commercial dual licencing



Andrew Donnellan wrote:
> On 4/21/07, Shriramana Sharma <samjnaa@gmail.com> wrote:
>> Say someone creates a library libfoo in the C language. The library is
>> dual-licenced -- under the GPL and under a commercial licence. GPL is
>> for open-source consumers and commercial licence is for closed-source
>> consumers.
>>
>> Now I create Python binding to that library - pyfoo. Now I would like to
>> dual-licence it myself, under the same terms -- GPL and a commercial
>> licence.
>>
>> Now to get the right of dual-licensing, do I have to obtain a commercial
>> licence from the author of libfoo?
>>
>> If yes, why? If no, why not? Please elucidate. Thanks.
> 
> If you created the bindings using ctypes or similar, where there's no
> actual linking taking place, I think it's all OK.

The specific technical mechanism used to link to libfoo doesn't matter.  For
the purposes of the GPL, it matters whether pyfoo forms a derivative work of
libfoo.  Whether that holds true for pyfoo or not depends on the details of
pyfoo and libfoo.  In the absence of strong technical evidence to the
contrary, or specific precedent, I suggest you assume that pyfoo does derive
from libfoo (regardless of the interface pyfoo uses to invoke libfoo).

> However, I think a nice email to the author can clear it all up anyway
> - your Python bindings would simply drive more sales of the commercial
> license anyway.

Agreed.

- Josh Triplett

Attachment: signature.asc
Description: OpenPGP digital signature


Reply to: