Re: Lilypond \include statements and the GPL

[Joseph Rushton Wakeling]

On 04/02/2013 11:28 PM, Anthonys Lists wrote:
> A derivative work is whatever the LAW says it is (whatever that is :-). NO 
> open
> source licence defines the term "derivative work", although they may give 
> their
> own interpretation of what they think it is.

The actual GPL term is a "covered work", and is specified reasonably precisely.

My little program calls functions from an explicitly GPL-licensed library -- not
from an API with multiple different implementations -- ergo, it's based on a
GPL-licensed work and is a "covered work" in the terms of the GPL.

> The whole point of open source licences is they are LICENCES. They GRANT
> PERMISSIONS.

Indeed, and a consequence of distributing a "covered work" under
GPL-incompatible terms is that you lose the permissions granted under that 
license.

So, if I'd tried to put a proprietary license on that bit of C code I shared,
for example, I'd have been violating the terms of the permissions granted me on
the GNU Scientific Library; so I'd have lost my right to use the GNU Scientific
Library; and if I continued to use it, I could be sued for using copyrighted
software without permission.

_That's_ where issues of copyright violation come in, not in the question of
whether my piece of code is strictly derivative in the sense of copyright law.