Yes, engravings *can* be protected by ip protection laws. But does not really matter. Karstens point is that the GPL applies to Lilypond code because he claims that an engraved score can be considered as a program compiled from the source file. But that is mostly just an analogy. PDF isn't even a full general purpose language (though PS would be). But even more: Usually the "compiled" PDF and the code in the source differ in functionality. We can have a scheme code snippet of any functionality in our code, but the resulting PDF won't have that functionality. So it is quite far stretched to view the generated PDF as a "program compiled from the Lilypond source". Rather the Lilypond source should be seen as some sort of document description language combined with Makefile like control commands.
The one exception of this is of course PS code, but not any piece of code falls unter protection laws. A simple PS draw command probably doesn't. So while it would technically possible to include PS commands that would fall under GPL terms there probably no reason for it. Also that code might still not even make it into the PDF in some equivalent way. And of course these things do not matter if you distribute a printed form. The only two problematic things I can see are: Some snippet might print something protected into the score, or missing permission to use the snippet (which only applies if the snippet is not licensed at all). But then probably one can argue that a piece of code posted on the internet implicitly permits you to use it internally. Cheers, Valentin
