Re: GSL random stuff and licensing

[Jon Trowbridge <trow@emccta.com>]

On Wed, Apr 14, 1999 at 09:14:47AM -0600, James Theiler wrote:
> ] Any thoughts on why gsl is GPL rather than LGPL? Any chance I might be able
> ] to use gpl code in Swarm under LGPL terms? 
> ] 
> ] <I hate this stuff -- I didn't decide to contribute to open software just
> ] so we could get into lawyerly fights over licensing!>
> 
> I hear you!
> 
> I think, though, that gsl is pretty well committed to GPL, and I can
> imagine that it could lead to a 'clash of licenses' to use GPL'd software
> in an LGPL'd package.

Indeed, it is a violation the GPL.  LGPLed code can re-licensed under
the GPL (this is allowed by clause 3 of the LGPL), but you can't go
the other way.

> Of course, I'm no lawyer.  I'll attach remarks by
> Stallman in favor of GPL, but I realize that doesn't address the immediate
> problems at hand. 
> 
> 
>    Why you shouldn't use the Library GPL for your next library
> 			   -- Richard Stallman
<snip>
> Using the ordinary GPL is not advantageous for every library.  There
> are reasons that can make it better to use the Library GPL in certain
> cases.  The most common case is when a free library's features are
> readily available for proprietary software through other alternative
> libraries.  In that case, the library cannot give free software any
> particular advantage, so it is better to use the Library GPL for that
> library.
<snip>

This is the key point that I think is often overlooked.  From the
point of view of strategy, the LGPL should be used for libraries that
provide functionality that is available from non-free libraries.  This
cannibalized the users of the non-free libraries: the LGPLed library
might end up being linked to a non-free application, but at least the
creators of that non-free application will be using the LGPLed library
instead.  This slightly reduces the profits of the non-free software
vendor, and the users might contribute bug fixes and enhancements back
to the LGPLed library.  Since the creators could have just used the
non-free library anyway, the LGPLed library has not really "aided and
abetted" the creation of any non-free software.  On the contrary, the
LGPL can potentially get paid developers of non-free software to
contribute labor to our cause.  (This is what is happening with a
LGPLed library that I've been developing...)

On the other hand, a "novel" library for which there is no non-free
alternative should be GPLed.  Then people have no choice: if they want
to benefit from the features offered by that library, they have no
choice but to also GPL their application.

The decision to GPL gsl (acronym overload, anyone?) has always puzzled
me, since most of its functionality seems to also be available from a
number of non-free sources.  This seems to be counter-productive, but
I admit that I'm not familiar enough with non-free numerical computing
libraries (like IMSL, NAG, etc.) to really assess them relative to gsl.

-JT