[AstroPy] SOFA license letter (draft)

[James Turner]

>> I haven't thought hard about what constitutes a derivative work in
>> Python generally, when there's no difference between source and
>> executables (other than pyc files).
>
> What about modules that include C code?
>
> Best
>
> Ole

If the C code is statically linked in, then according to the
FSF the module would definitely be a derivative work. If it's
dynamically linked, it might depend on the details -- eg. can
the module still run if the dependency is not present and can
some alternative code implementing the same ABI satisfy the
dependency?. If you had an astrometry module linked to SOFA,
that would probably be a derivative work and I think probably
the Python application would be too (though the latter might
be debatable).

Cheers,

James.