[SciPy-dev] PRIMME: PReconditioned Iterative MultiMethod Eigensolver

[Robert Kern]

Gary Ruben wrote:
> Hi Brian,
> The issue is not one of convenience. The issue is that the GPL and LGPL 
> are legally and practically incompatible with the scipy/MIT licence and 
> would require a change of the scipy licence is any of their code were to 
> be included with the existing package.

No, it wouldn't. scipy's license is compatible with the GPL in that one can 
combine scipy code and GPLed code just fine without relicensing anything. The 
scipy license grants strictly more freedoms than the GPL.

However, the longstanding *policy* of the scipy project is not to include code 
with more restrictions than the BSD license. There are some exceptions made for 
certain wrappers which are strictly optional like FFTW.

> What I'm unsure of if whether 
> it's OK to combine GPL and LGPL code (and GPL3?) into a single package. 

Yes, they are constructed explicitly to allow that.

> My guess is that it's not and that this means a proliferation of extra 
> packages are required. If this is the case maybe they should be called 
> scipy_gpl and scipy_lgpl or scikits.gpl, scikits.lgpl or something. 
> Maybe there can be an individual egg for each one which carries the 
> relevant licence around.

There's no point in that. Each scikits.* subpackage can have its own license. 
There will be no "scikits license" that applies to everything distributed in the 
scikits namespace. Users of each package are responsible for obeying the 
conditions of the licenses. That they are in the same SVN repository is "mere 
aggregation" as the term is used in the GPL and LGPL.

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco