Re: Lilypond Feta font license

[Joseph Rushton Wakeling]

On 10/18/2012 09:38 AM, Han-Wen Nienhuys wrote:
> The idea behind this is twofold: first, the GPL does not make sense
> for a font.

That's not entirely true.  Obviously it's not a good condition for use of a font 
in a document, and you _can't_ copyright the _appearance_ of the font, but it 
makes sense for GPL to be applied to the underlying "code" of a font so long as 
you have an exception in place that permits embedding in a document -- see:
https://www.gnu.org/licenses/gpl-faq.html#FontException
https://www.fsf.org/blogs/licensing/20050425novalis

> Second, the font can be used independently of LilyPond,
> and thus it is in a sense a standalone work, the use of which does not
> create a derivative work.

Yea, this seems a broadly correct assertion with respect to fonts although the 
precise interpretation might differ depending on whether (and how) you bundle 
the font together with other software.

On a related note, this raises the issue of how Lilypond itself bundles the 
fonts -- as an internal part of Lilypond, or to install as a system font?  See:
https://bugs.launchpad.net/ubuntu/+source/lilypond/+bug/174369

AFAICS this latter issue is why e.g. if you open up a Lilypond-generated SVG, 
PS, etc. in Inkscape, all the Feta font characters display as gobbledegook.

> Although, this project in particular is not GPLd, questions about
> using Feta have popped up from time to time before from others, and
> the OFL is a way to answer all these questions in one fell swoop.

Even with just GPL+exception (the embedding exception is important; is it in 
place for Feta?), it's most likely possible for a non-GPL, even proprietary, 
application to use the Feta font, and even distribute it as part of a collection 
of software, so long as the font is included as a standalone element and not 
integrated into the code in other ways.  It may be worth touching base with FSF 
and related bodies on this.

But (GPL+exception)+OPF is a fairly standard way to licence a font and does 
remove uncertainties on the part of other software developers.