[GRASS-dev] gmath and gpde update

[Moritz Lennert]

On 13/01/09 23:43, Glynn Clements wrote:
> Moritz Lennert wrote:
> 
>>> The GPL allows you to charge for derivative works (although being
>>> unable to prohibit free redistribution tends to limit this).
>>>
>>> Anyone distributing GRASS binaries is required to provide (or offer to
>>> provide) the source code for "the work as a whole" (which would
>>> include meschach) under the terms of the GPL.
>>>
>>> This would then allow the recipient to extract any part (e.g. 
>>> meschach) and (try to) sell it. While that seems like a rather
>>> unlikely scenario, the GPL requires that you permit this, and if you
>>> cannot permit it, you cannot satisfy the GPL.
>>>
>>> And the meschach library appears not to permit it.
>> That's what I thought...
>>
>> Interesting that Debian thought it DFSG-compatible...
> 
> I don't really see a problem with it. It's a "you do not have the
> freedom to make this program less free" restriction, similar to the
> restrictions imposed by the GPL.

Well, the first paragraphe of the DFSG is:

"Free Redistribution

The license of a Debian component may not restrict any party from 
selling or giving away the software as a component of an aggregate 
software distribution containing programs from several different sources."

So, forbidding to sell seems against the DFSG...

> 
> Essentially, it's a question of how to resolve competing freedoms, and
> the meschach licence took a different view to the GPL. It's just a
> different (and incompatible) sort of "free".

There seems to be a possibility of exceptions for these situations in 
the GPL[1]:

"If you're using GPLv2, you can provide your own exception to the 
license's terms. The following license notice will do that. Again, you 
must replace all the text in brackets with text that is appropriate for 
your program. If not everybody can distribute source for the libraries 
you intend to link with, you should remove the text in braces; 
otherwise, just remove the braces themselves.

"
[License text]

In addition, as a special exception, the copyright holders of [name of 
your program] give you permission to combine [name of your program] with 
free software programs or libraries that are released under the GNU LGPL 
and with code included in the standard release of [name of library] 
under the [name of library's license] (or modified versions of such 
code, with unchanged license). You may copy and distribute such a system 
following the terms of the GNU GPL for [name of your program] and the 
licenses of the other code concerned{, provided that you include the 
source code of that other code when and as the GNU GPL requires 
distribution of source code}."

and something similar exists in GPLv3:

"Additional permission under GNU GPL version 3 section 7

If you modify this Program, or any covered work, by linking or combining 
it with [name of library] (or a modified version of that library), 
containing parts covered by the terms of [name of library's license], 
the licensors of this Program grant you additional permission to convey 
the resulting work. {Corresponding Source for a non-source form of such 
a combination shall include the source code for the parts of [name of 
library] used as well as that of the covered work.}"

So, we might be able to do this, but AFAICT this would need the 
agreement of all people holding copyright over GRASS code. So, it might 
be easier to convince the meschach authors. Soeren, maybe you could 
contact them ?


Moritz

[1] http://www.gnu.org/licenses/gpl-faq.html#GPLIncompatibleLibs