Re: Font license recommendation

[Jeff Licquia <licquia@debian.org>]

On Sun, 2002-08-04 at 17:53, Lars Hellström wrote:
> At 00.53 +0200 2002-08-03, Thomas Bushnell, BSG wrote:
> >Lars Hellström  <Lars.Hellstrom@math.umu.se> writes:
> >
> >> I doubt this argument could work. However if it did then it certainly would
> >> provide a technical solution to the (obnoxious?) GPL incompatibility
> >> problem: just design the linker so that it pads the executable with markup
> >> saying "beginning/end of material that is part of the work XXX", and then
> >> claim the file is an aggrevation of different works, which just happens to
> >> be interpreted as an executable program by the OS.
> >
> >Since things like intention matter--and not just technical
> >mechanism--this is just FUD.
> 
> "FUD" ?
> 
> On what do you base your opinion that intent has any significance for
> whether the GPL allows an action? 

Well, there's this:

"The source code for a work means the preferred form of the work for
making modifications to it." (section 3)

"Preferred" is an intent, last time I checked.  It's used against people
who use obfuscators on their source before distribution, for example,
because no one in their right mind would intend to edit the obfuscated
source to add features or fix bugs.

There's also this:

"The act of running the Program is not restricted, and the output from
the Program is covered only if its contents constitute a work based on
the Program (independent of having been made by running the Program). 
Whether that is true depends on what the Program does."

"What the Program does" is also intent.

Incidentally, the latter paragraph also provides reason to believe that
a PostScript file generated using a GPL font does not become "tainted"
with the source requirements of the GPL.  (No, it's not clear-cut; I'm
not necessarily arguing that it's the case, just that it's possible.)

> It clearly says
> 
>   You may not copy, modify, sublicense, or distribute the Program
>   except as expressly provided under this License.  Any attempt
>   otherwise to copy, modify, sublicense or distribute the Program is
>   void, and will automatically terminate your rights under this License.
> 
> and I don't see any reference in it to the intent of the licensee (only to
> the intent of the license, but that is something quite different).

That's because intent is a subject of other parts of the license.

> Furthermore I don't see that there would necessarily be any difference in
> intent. Certainly if one writes a program whose only purpose is to
> demonstrate a legal loophole there would be a difference in intent, but
> that isn't the interesting case. In the interesting case the intent is to
> "make a single file program, incorporating various pieces of free software
> (some of which are GPL and some of which are GPL-incompatible), that does
> X". The "X" could be to display a certain picture; PS files can have this
> intent, but there are also C programs with the same intent.

Well, let's take the Gimp.  It processes one image file into another,
and is GPLed.  Does that have any implication on the legal status of
either image?  What if the original is GPLed?  Especially given that
most image formats are their own preferred format for modification,
things are not so clear as they might seem.

One could make the case that a font is an interpreted language, with the
font renderer as the interpreter.  In that case, a rendered glyph could
be considered "output from the Program".  OTOH, the font could be
considered data that is input by a font renderer; in that case, the
rendered glyphs could be considered "derived works".

Then again, if you're using the Gimp to create a PNG with text rendered
in a GPLed font, it wouldn't matter; the PNG file is its own "preferred
format".  But an EPS or SVG might, especially if the font is required to
process the file properly.  Indeed, a vector image file format could
itself be described as a program; PostScript is even considered Turing
complete, if my memory serves me.  But what if you convert a PNG to an
EPS, and add some text with a GPLed font?  What constitutes "the
source"?  If the PNG is proprietary, have you just violated the GPL?

The details of embedding could even make a difference.  One could embed
bitmaps generated by the font instead of the font itself, which would
clearly be "output from the Program".  Bitmap fonts would themselves be
in the "preferred form", so their licensing status might not matter; at
that point, what would it matter if the fonts were embedded in another
file?

In short, I don't think the question is as simple as you make it.

> And just to make sure we're clear on what my point is: Incorporating a
> GPLed font in a PS document does, in contrast to what you claimed, have (in
> many cases) unwanted legal implications; if it didn't then there would be a
> simple workaround for GPL-incompatibility.

That's entirely possible, but I remain unconvinced.