[quake3] Re: gpl anticheater

[tom fogal]

 <20050905014924.40591e2e.tim at ngus.net>Tim Angus writes:
> On Sun, 4 Sep 2005 12:46:45 -0700 Zachary wrote:
> > I personally don't think any GPL punkbuster style program would be
> > effective, though I would certainly welcome people to try.
> 
<snip>
> The double whammy is that since Q3 is now GPL, it cannot be distributed
> with any closed source libraries. So implementing a free-as-in-beer
> alternative to punkbuster is hampered slightly. Correct me if I'm wrong
> (IANAL etc.), but there is no problem with a GPLed application linking
> against a non GPL library? <snip>

I am fairly (but not 100% sure) that this is illegal as per the GPL, if
done at link time... thats why the LGPL was developed.

See this quote from the bottom of the GPL page on gnu.org[1]:

   This General Public License does not permit incorporating your
   program into proprietary programs. If your program is a subroutine
   library, you may consider it more useful to permit linking
   proprietary applications with the library. If this is what you want
   to do, use the GNU Lesser General Public License instead of this
   License.

I take this to mean that a non-GPL program cannot link in a GPL
library, and to imply that the converse is true.  Of course, this text
isn't actually part of the license, just a little hint at the bottom.

> At least, not if you dynamically load the
> library at runtime as Q3 does with libGL. Right?

Dynamic loading really obscures the issue... I'm not sure...

-tom

[1] http://www.gnu.org/copyleft/gpl.html