Re: [gtk-list] Re: Gtk+ Commercial Applications (Licencing Issues)

["Robert G. Brown" <rgb phy duke edu>]

On 5 Oct 1999, Preben Randhol wrote:

> "Robert G. Brown" <rgb@phy.duke.edu> writes:
> 
> | On Tue, 5 Oct 1999, Rob Huffstedtler wrote:
> | 
> | > You need to reread the GPL.  The reason the LGPL used to be called the
> | > Library GPL was so that you could link proprietary apps against it.  YOU 
> | > CAN NOT LINK A NON-FREE (SPEECH) APP AGAINST A GPL'ED LIB.  For
> | > instance, you cannot link a proprietary app against libgtop.  If you
> | > don't believe me, tool on over to www.fsf.org and reread the licenses.
> | 
> | Not to pick a nit, but of course you can.  You just cannot sell it.
> 
> I thought you had to release to code...

As the man said, go to:

http://www.fsf.org/copyleft/copyleft.html

and read them.

Note well that NONE of the GPL (library or otherwise) versions state
that you have to release code in which you use GPL programs or link to
GPL libraries -- after all, how can they do that?  It isn't theirs to
give away!  Also, what are they going to do, make you set up a website
for distribution?

Rather, the GPL states very clearly that you are FREE to use the
software or libraries for any purpose whatsoever -- that's the whole
point.  However, IF you use a GPL source (or in some cases link to a
GPL library) AND you want to DISTRIBUTE the program thus derived from
the GPL source, you must (in VERY condensed form):

  a) Include the original GPL notice in the headers and
  b) Accompany it with the source code (or offer to make it available
in a reasonable form "on demand") or
  c) tell somebody how YOU got the source code (in the case of binary or
object distributions).

Note the key word -- distribution.  The GPL doesn't prevent you from
selling something you wrote derived from GPL code, it just says that you
have to give away the source on demand if not with the item sold.  It
also says nothing whatsoever about "internal" distributions in a
corporate setting, where it is irrelevant whether or not b) holds as it
is the corporate entity that matters, not the desktop workstation in the
company.

I'm not absolutely certain what the legal status would be of a program
written in a corporate setting for their own private use (derived from a
GPL source or library) in the event that an employee transferred the
program to a third party without permission.  It might well be that the
company could not legally prohibit such a transfer or any subsequent
transfers after the fact (difficult to judge, though).  They could, of
course, fire the employee.  A judge MIGHT well give them the right to
block further transfers of the program if he/she determined that a) the
derived work was done for internal use only and b) the derived work
contained elements that were unique and hence might have been considered
"proprietary".  

The point is that you don't give up a copyright on your OWN code if you
right something that uses a GPL source for part of it -- you just cannot
transfer COPIES of the integrated product without it "inheriting" the
GPL from the GPL fragment.  I would even guess that if you de-GPL'd the
sources you would retain the copyright on your contribution even in this
case.  In any event, I hope to never find myself in such an evil legal
tangle...;-)

All this both is, and isn't, a bit off-topic, (and I tried the short
version of the answer FIRST) but a lot of this is fairly important to
understand for anybody working with GPL software and libraries in any of
its variants, and that certainly includes this group.  The GPL is
intended to free developers to develop.  It isn't a pair of handcuffs
and although it is clear that the FSF would LIKE for all software
products to be free they do put practical (and fair) limits on their
arm-twisting.  

        rgb

Robert G. Brown	                       http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb@phy.duke.edu