Proper license note for Maxima and Maxima-derived works

On 12/06/2012 12:13 PM, Stefano Ferri wrote:
> First: what kind of copyright notice should I put in the header? The 
> files in my distribution have a header with such informations, but 
> here I don't know what to do. The original merror.lisp, as many 
> (pretty all) other Maxima source files, doesn't contain a rigorous 
> license notice; it simply states "The data in this file contains 
> enhancements", with a simple Copyright(c) with years and names, and no 
> indications about the program they are part of. There is a copyright 
> notice in the main level of source tree, with attached a GPL v2, but 
> this doesn't seem the correct way to do that. It is not clear if the 
> license is the Gnu GPL version 2, or version 2 with the option for 
> later versions.
I would not say that not having a GPL header in every file is incorrect. 
It is just not following the recommendation but that does not invalidate 
the fact that Maxima is released under GPL 2.

Regarding whether there is an option for GPL versions later than 2, my 
opinion is the following:
In the sentence that says "either version 2 of the License, or  (at your 
option) any later version" the part "your option" refers to you, as a 
user, and not to the authors. That means that the authors have already 
granted you the right to release parts of Maxima with your code that is 
being released with version 3 of the GPL.

Only in the cases when the authors state explicitly that you MUST use 
only version 2 of the GPL you have to use that same version number. The 
default GPL 2 is already compatible with GPL 3 or later versions.

Keep in mind that I'm not speaking on behalf of the Maxima developers. 
I'm just telling you the answer I gave several times to people 
contributing code to the Savannah repository, during the years that I 
worked as a volunteer for the FSF, being in charge of accepting or 
rejecting non-gnu projects in Savannah.

Regards,
Jaime