[Pkg-exppsy-maintainers] Licensing

[Christoph T. Weidemann]

Hi all!

First of all congrats to the first release of PyMVPA and thanks for
all the hard work! I'm looking forward to using and contributing to
it!
I have a question / suggestion regarding the license of PyMVPA: Is
there any good reason for PyMVPA to use the MIT license rather than
the GPL? If there's no compelling reason to use the MIT license, I
would like to suggest abandoning the MIT license and switching to the
GPL. I'll try to lay out my reasoning behind this suggestion below.

I think the requirement to pass on the freedom that comes with GPL
licensed software to anybody it is re-distributed do (modified or not)
has done a lot for the spread of free software. In short, I think it's
pretty safe to assume that without this requirement there would be
less free software today. Likewise, I think it's reasonable to assume
that new software that is released with such a requirement, will
increase the chances that new software that builds on it will also be
free. Thus, using the GPL in favor of more permissive licenses is
benefiting the free software community. The following text makes a
strong case why the GPL is a better way to promote the freedom of the
users than more permissive licenses such as the one currently adopted
for pymvpa:
http://www.fsf.org/licensing/essays/why-copyleft.html

There's also a long (but interesting) essay by RMS on the GNU project
that (among other things) discusses this issue:
http://www.gnu.org/gnu/thegnuproject.html
(alternatively you can access this essay by hitting C-h C-p in Emacs)
The sections most relevant to the issue of licensing is the one titled
"Is a program free for every user?", "Copyleft and the GNU GPL", and
"The GNU Library GPL". As pointed out in that last section, it does
make sense (from the point of view of promoting free software) in some
cases to use a more permissive license than the GPL, but to me it's
pretty clear that PyMVPA is not such a case.

I would also like to point out that a dual licensing scheme in which
users could pick between the MIT license and the GPL would not ensure
user's freedoms as effectively as using the GPL as the only license
(indeed from the point of promoting users' freedoms such a dual
licensing scheme would provide no improvement over just using the MIT
license alone).

Thanks for hearing me out!
Best,
Christoph