Re: Lilypond as a LGPL library?

[David Kastrup]

Mathias Kozlowski <address@hidden> writes:

> Hi everybody, I'm new to Lilypond's world. 
> I'm really impressed by the possibilities and the rendering quality of your
> compiler.
>
> I'm currently starting a new project, some sort of sequencer. I'd like to have
> in it a score editor with a graphical interface. Lilypond is a perfect
> candidate for providing the engine of this score editor. But:
> - it will be a commercial program (not under GNU GPL)

You mean proprietary.  Most popular Linux distributions _are_ commercial
while making a point of consisting of freely redistributable software.

> - for performance reasons, I'd like to transform Lilypond into a
> library with a custom output-*.scm file rendering directly into my
> GUI.
>
> Concerning GNU GPL licensing, my understanding is that I could embed
> the compiler in a commercial solution because of separation of
> executables (like some commercial IDEs around GNU GCC).

Depends on what kind of glue you stick in the executables.  As long as
your Lilypond is unchanged, or your glue code is not specific for your
application and accepted into the upstream distribution of Lilypond, you
should be reasonably safe.

> Since I need to transform Lilypond into a library, my commercial
> requirement breaks the GNU GPL license.
>
> In a post of Erik Sandberg in this mailing list (New attempt on
> tuplets/percent repeats, Mon, 15 May 2006), I found:
>
> The main change I'm thinking of, is to LGPL parts of lily (separate a
> lib around Context and Dispatcher), so non-free programs can use the
> music stream interface in a lilypond-compatible way. I doubt anyone is
> interested, but it may be a bad thing to prohibit it.
>
>
> Actually, I'm VERY interested in such a solution, so any news about it?

The way I understand the proposal from what you quote, it would not help
you much.  It would provide a music stream handling framework, but not a
typesetter.

-- 
David Kastrup