Re: linking to GPL'd libraries WAS Re: One unclear point in the Vim license

[Philip Thiem <ptt@umr.edu>]

On Thu, Jan 03, 2002 at 06:29:50PM -0800, Thomas Bushnell, BSG wrote:
> lloyder@canada.com writes:
> 
> > If a library's interface is implemented to a standard or similar,
> > than someone linking to a GPL library version should be alright, no?
> 
> No.  Actually linking to the GPL'd library is not allowed if you are
> doing so from non-GPL-compatible code.
> 
> 

The GPL is written to specifically prevent someone who would normally
have to modify or copy parts of a non-library GPL'ed program's source(and
thus releasing the changes under the GPL), instead turn parts of it 
into a GPL'ed library(effectivly copying,but perfectly fine) making any 
"changes/additions" outside the once non-library code and releasing the 
final product where the intent is clearly to copy GPL code and use it 
in a non-GPL compatible program. Here the fact that the code is now 
a library form is merely a technicality.  So linking must be considered
forming a derived product, and forbidden.

If an author chooses to release he code under the GPL he
states his intent that the code cannot be used under programs with non-GPLed
licenses.  If the author wants to allow this specifically, then the author
shoud use the LGPL.

Philip Thiem