The Industry choice

Jeff Shannon jeff at
Fri Jan 7 14:33:42 EST 2005

Paul Rubin wrote:
> Jeff Shannon <jeff at> writes:
>>Note that the so-called 'viral' nature of GPL code only applies to
>>*modifications you make* to the GPL software.  
> Well, only under an unusually broad notion of "modification".  

True enough.  It can be difficult, in software development, to define 
a distiction between a situation where two software products are 
distinct but cooperative, and a situation where one software product 
is derivative of another.  Stallman has chosen a particular definition 
for use in the GPL; one may debate the value of using this definition 
over any other possible definition, but the line had to be drawn 
*somewhere*.  (And given Stallman's philosophies, it shouldn't be too 
surprising that he's drawn it about as broadly as he reasonably could.)

>>(Problems may come if someone licenses a library under the GPL; that's
>>what the LGPL was invented for.  But the issue here is not that the
>>GPL is bad, it's that the author used the wrong form of it.)
> The "problem" is not a problem except that in the case of some
> libraries, simply being able to use a library module is often not
> enough incentive to GPL a large application if the library module's
> functionality is available some other way (including by
> reimplemntation).  If the library does something really unique and
> difficult, there's more reason to GPL it instead of LGPL'ing it.

To my mind, the intent of the GPL is "use it, but if you change it or 
make a derivative, share the changes".  With libraries, though, you 
*can't* use it without hitting the FSF-specified definition of a 
derivative.  The LGPL exists to make it clear that, for libraries, the 
common meaning of "using" and "changing" are different than they are 
for applications.

Of course, there's nothing that stops people from insisting that, if 
you *use* their libraries, anything you use them for must be 
free-as-in-speech (which is the effect of using the GPL instead of the 
LGPL); it's the author's choice what restrictions should be put on the 
software.  But the usage-restrictions on a library under GPL are more 
severe than they are on an application under GPL.  The unfortunate 
thing, in my opinion, is that a fair number of library authors don't 
think about that when they GPL their code.

Jeff Shannon
Credit International

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