On Wed, 2019-10-30 at 01:36 +0100, David Kastrup wrote: > Karsten Reincke <k.rein...@fodina.de> writes: > > > [...] > > > > Hence, if I use a piece of software as library, snippet, or module, > > then I am using the advantage that I do not have to program that code > > by myself. I am saving costs and time. A very good indicator, that I am > > saving resources by using the prework of another programer, is the call > > of a function (or method or similar). Therefore, calling a function / > > method delivered by a GPL licensed software indicates that I create a > > derivative work and that the strong copyleft effect is triggered. > > Which would imply that distributing your LilyPond input combined with > OpenLilylib code would require licensing your LilyPond input under the > GPL. Yes, exactly. That's my point. > > It doesn't cover the output of running your LilyPond code, namely the > PDF.
I am afraid that this statement does judicially not hold: LilyPond itself says that it works "[...] as a compiled system: [...] In some ways, LilyPond is more similar to a programming language [...]". Hence the viewpoint of Carl Sorensen seems to be valid: LilyPond is like the gcc. And even in case of the gcc, the copyleft effect does not cover the outpout (the compiled program). But in case of a GPL licensed LilyPond snippet (sic!), the copyleft effetc is triggered by the use of that snippet. And the GPLv3 is very clear: §4 and §5 require us also to distribute the code of the embedding / using work under the terms of th GPL. And - under the title "Conveying Non-Source Forms" - §6 requires us also to distribute our non-source forms under the terms of the GPL. Here, the analogy of gcc and Lilypond matches perfectly: As we are must distribute binaries which are compiled by the gcc on the base a GPL licensed source code, we must also distribute the binaries (png) which are compiled by LilyPond on the base of a GPL licensed LilyPond score description. It is exactly the same case. I regret to be the messenger of bad news. But there is a simple solution: Don't use GPL licensed LilyPond snippets, if wou want to keep you rights. And perhaps convince the OpenLilyLib developers to relicense their work. with best reagards Karsten -- Karsten Reincke /\/\ (+49|0) 170 / 927 78 57 Im Braungeröll 31 >oo< mailto:k.rein...@fodina.de 60431 Frankfurt a.M. \/ http://www.fodina.de/kr/