On 22. Sep 2020, 19:30 +0200, Tim McNamara <timmcn@bitstream.net>, wrote:
On Sep 22, 2020, at 10:20 AM, Partitura Organum <partitura.org@gmail.com> wrote:
Karsten […] mentioned the lilypond-files: "OpenLilyLib is licensed under the GPL. Thus, the copyleft effect forces that all Lilypond files which include OpenLilyLib files, have also to be distributed under the terms of the GPL.". Thus, if I use OLL in my lilypond and I want to make my lilypond files public, I have to do so under the GPL v3 license.
Or so Karsten states.
Secion 5 of GPL v3 does seem to imply this. The question here is whether typing something like "include oll.ily" in your own ly-file makes your ly-file a derivative work of OpenLilyLib. If "yes" the GPL v3 license demands you license your ly-file as GPL as well if you ever publish it. If "no", well then it is for you to decide which license works best for you.
Calling what amounts to a subroutine does not cause the subroutine to own the output, which is IMHO all that is being done with "\include oll.ily” (or any \include commands) so the answer to the question is “no.” One may publish one’s input file, although the utility of that is questionable except as a teaching tool, under whatever license one wishes. That may cause a cognitive conflict with the GPL for some users. One may publish the output of the application under whatever license one wishes, including standard copyright within the jurisdiction where one lives. Were the GPL to require creators to license their output under some specific copyleft arrangement, few people would use any GPL software. And indeed, there may be people/entities that refuse to use free software due to that misunderstanding. Lilypond and/or the GPL does not own the user's input or output files- any more than Microsoft owns all documents written in Word- as that would of course contravene the notion of freedom in free software.
I am curious- is there a parallel discussion among LaTeX users? I’ve never used LaTeX nor been part of discussions in the that community, but the operating similarities are strong (a text input file with formatting markup producing an output file such as a PDF).
If one creates a word processing document using a font, whether copyleft or copyright, does the document publishing have to adhere to the licensing of the font? Of course not.