[Openfontlibrary] Why GPL fonts without source from first copyright holder are redistributable

[Dave Crossland]

On 13/01/2008, Ben Laenen <benlaenen at gmail.com> wrote:
> On Sunday 13 January 2008, Christopher Fynn wrote:
> >
> > > a GPL font without sources may not be redistributable.
> > > ...
> > > Here is the full relevant text from the GPL:
> > >
> > > "The source code for a work means the preferred form of the
> > > work for making modifications to it. For an executable work,
> > > complete source code means all the source code for all
> > > modules it contains, plus any associated interface definition files,
> > > _plus_the_scripts_used_to_control_*compilation*_
> > > _and_installation_of_the_executable_."
> > > -- http://www.gnu.org/licenses/old-licenses/gpl-2.0.html (1991)
> >
> > Are fonts  independent "executable works" or just collections of data in
> > publicly documented formats (pfb, ttf, otf) supplied to an executable (the
> > rendering engine)?
>
> Since GPL requires redistribution of the source when
> one makes modifications, or if you just redistribute it yourself, fonts
> like the Liberation Fonts are effectively unredistributable.

I said that a GPL font without sources _may_ not be redistributable,
not that fonts like the Liberation Fonts are effectively
unredistributable. Here's why:

The original binary from the initial copyright holder is the "de
facto" source. You need to distribute the verbatim binary as part of
your source bundle.

(I think that's what Karl was getting at :-)

In detail:

Section 3b of GPLv2 says that you only need to distribute an offer for
a source bundle, valid for 3 years, so you don't need to confuse a
client who has commissioned "Laenen Sans" by distributing to them both
Liberation Sans and Laenen Sans. However, I'd recommend distributing a
"source bundle" marked as such (like in a single zip file) as part of
the client deliverables so that you don't have to worry about
maintaining backups of the source yourself for 3 years.

Also, remember that only the copyright holder can sue for
infringements of their copyright terms.

Can Red Hat sue someone for distributing Liberation _verbatim_ without source?

No. Red Hat distributed Liberation without source, so it is a paradox
that they would sue someone else in order to require that person to
release source, because for that person to do so would require them to
release the source. Instead, because they are the initial copyright
holder, the original binary from them is the "de facto" source.

, what does my source bundle includeIf you modify Liberation, and
redistribute it without source, can Red Hat sue you?

Yes. Red Hat distributed Liberation without source, so that binary is
the "de facto" source for their contribution to the work, and so you
need to distribute the verbatim binary as part of your source bundle.
If your source bundle lacks the source for your contribution, you risk
being sued by them. Hypocritical, but entirely possible.

If you modify Liberation, and redistribute it with your source for a
proprietary program, like a VFB, will Red Hat sue you? No. Source is
fine even though it is caught in a "java trap."
(http://www.gnu.org/philosophy/java-trap.html explains)

If I then modify your Liberation, and redistribute an OTF without your
source binary VFB and without Red Hat's "source" binary TTF, can Red
Hat sue me? Yes. Can you sue me? Yes.

What does my source bundle include if I use FontForge to derive my
work from the OTF that you generated from your VFB that you dervied
from the TTF?

* Red Hat's original TTF file
* Your VFB file
* Your python script file
* Your VOLT script file
* Your OTF file
* My SFD file
* My XGF file
* My python script file

Is this ugly?

Yes.

Is this guaranteeing the maximum freedom for all users and developers
of the font?

Yes.

> ...
> Sure, if they want OFL, good for them, I'm not pursuing the source for
> those fonts then (even though it would be nice to have), but could we
> keep GPL for the fonts *with* source code, as the GPL requires?

The OFL is great for introducing people to the free software+culture
movement, like the CC licenses are, and SIL says that source for OFL
fonts is nice to have and recommends it.

Consider if Red Hat used the OFL, and people volunteered to include
their sources as above. That would mean I could distribute a "clean"
set of my SFD/XGF and an OTF.

Would that be a disaster? No. Would that be less free? Yes.

-- 
Regards,
Dave