Re: Lilypond \include statements and the GPL

[Joseph Rushton Wakeling]

On 04/02/2013 03:52 PM, David Kastrup wrote:
> The main difference is "work as a whole" vs "mere aggregation".  If you
> include some file as a form of invoking its documented interface, you
> form no new combined work.

Indeed, which if I recall right is how Google was able to provide non-GPL'd
header files describing the Linux kernel API for use in Android.  (If I'm wrong,
let's not get into the reasons why -- it's another huge can of worms...:-)

> If, however, you include a file, then patch
> and access its internals, you are creating a new derived version of its
> contents, and that would be covered by the GPL.

Quite.

> With regard to linking executables, the FSF is of the position that
> linking generally constitutes creating a derived work (whether linking
> statically or dynamically), potentially via contributory infringement,
> thus forming a fundamental difference between LGPL and GPL.  I find that
> somewhat audacious, but short of actually decisive court precedents,
> most people (and corporations) prefer not putting this theory to the
> test.

Surely the fundamental aspect of it here is not whether traditional copyright
would consider a new work derivative of the GPL'd library it links to, but that
the terms of use of a GPL'd library state that you lose your rights to use and
distribute that library if you distribute work that links to it under
GPL-incompatible terms.

Anyway, back to the key issue -- would you like me to draft an email to the
Software Freedom Law Center?  The fact that this issue is of concern also to
people in the TeX community makes me feel that it's something they should
probably be alerted to.