Re: GPL - GSL and derivative work.

[Edwin Robert Tisdale <E dot Robert dot Tisdale at jpl dot nasa dot gov>]

Mark Galassi wrote:

> There is a discussion of these issues on the GNU web pages
> which matches what I say
> and is a legal opinion backed by the FSF's legal counsel.
> 
> If another identical API exists then you have a grey area.
> People have done the trick (in other software)
> of writing a low-quality compatible API
> that was public domain instead of GPL'd

Yes.  The worst tricksters are the FSF and the GNU project.
The GSL is, at best, simply another implementation of
the Basic Linear Algebra Subprogram (BLAS) library,
The Linear Algebra PACKage (LAPACK) and Numerical Recipes in C.

You can't force anyone to distribute the source code
for their application programs
simply because it uses the same API as the GSL.
If you could, then proprietary library vendors could require
a royalty from every program that used their API
even if it was linked to a GPL'd implementation.

> Regarding your comments on the use of the GPL instead of the LGPL,
> we are a GNU project and there are very clear reasons
> for the GNU project to promote using the GPL
> instead of the Lesser GPL for almost all libraries.
> See:
> 
> 	http://www.gnu.org/licenses/why-not-lgpl.html

There are better reasons to promote the LGPL instead of the GPL
for numerical libraries like the GSL.
But applying the GPL instead of the LGPL
is just one of the reasons why the GSL is doomed.
The GPL unnecessarily encumbers the GSL.
It does not make the GSL or applications that use it more free.

I believe that you mean well Mark but your attitude
is one of the worst enemies of free software.