Re: Use of GPL'd code with proprietary programs

[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).

> Some legal advise left us a little uncertain, and we are a bit
> sceptical.  As a key rule we are advised: "When using the part of
> the GPL that places restrictions on the distribution of programs
> that link against GPL'd code, legal restrictions only apply when
> the GPL'd code is /modified/.  We have not modified the GPL code.

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".

"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.

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."

Arnoud

-- 
Arnoud Engelfriet, Dutch patent attorney - Speaking only for myself
Patents, copyright and IPR explained for techies: http://www.iusmentis.com/