Re: Use of GPL'd code with proprietary programs

[Haakon Riiser]

[Arnoud Engelfriet]

> Haakon Riiser wrote:
>
>>  WMV9 decoder (proprietary)  |  MPEG-1/2 decoder (GPL)
>
> You may want to check your WMV9 license. Most versions I've seen
> explicitly forbid any kind of bundling with GPL-licensed software
> (even merely putting it on the same disc).

I haven't personally read it yet, but I'll do so ASAP.  If this
is the case for our license, we have to consider if it's even
worth bothering with WMV9. :-(  I can't even believe why they
would do such a thing -- are they afraid of getting infected by
the GPL license in some way?  Do they mention the GPL specifically?

> That does not seem to be accurate. The GPL explicitly states
> that you may only distribute "works based on" the GPL'ed program
> if you apply the GPL to that whole "work based on". It says
> nothing about "only if the GPL code is modified".

Here's what our lawyer said (more or less):

All restrictions on distribution of the GPL'd program appears under
GPL section 2, which specifically targets modified copies only:
(capitalization of key words were done by me)

  2. You may MODIFY your copy or copies of the Program or any
     portion of it, THUS FORMING A WORK BASED ON THE PROGRAM, and
     copy and distribute such MODIFICATIONS or work under the terms
     of Section 1 above, provided that you also meet all of these
     conditions:

     [...]

Since "a work based on the Program" is defined as "modified GPL
code", all the conditions and requirements that follow do not apply
when all we do is link an unmodified GPL library to our program.
Or so we were told.

> "Work based on" is defined as derivative work under copyright law
> and so this requirement kicks in for modified GPL code. But it
> also applies to the original, unmodified work. And according
> to the FSF it also applies to any work that links to the GPL
> code.

In light of what I said above, would you say that linking binary
code is included in "modify your copy of the Program"?

> A typical example is the GNU readline library. You need to link
> to this library to use its functionality. According to
> http://cnswww.cns.cwru.edu/php/chet/readline/rltop.html
> "This means that if you want to use Readline in a program that you release
> or distribute to anyone, the program must be free software and have a
> GPL-compatible license."

Funny that you should bring up readline, since this was the
very same example I presented to our lawyer when I expressed my
skepticism of his interpretation.  I know Stallman convinced
Bruno Haible to release CLISP under the GPL, so that it could
legally use the readline library:

http://cvs.sourceforge.net/viewcvs.py/*checkout*/clisp/clisp/doc/Why-CLISP-is-under-GPL

But again, I was told that none of this matters since the people
who wrote the license apparently had screwed up.  Their intention
was to prohibit linking, but that's not what the actual text says,
and that is the only thing a judge would consider.

-- 
 Haakon