15 Jan
2012
15 Jan
'12
6:36 p.m.
On Sun, 2012-01-15 at 17:35 +0100, Albert Graef wrote:
On 01/15/2012 12:57 PM, Aurélien Leblond wrote:
$ cat ~/Desktop/ams-2.0.1/COPYING
[snip]
9. The Free Software Foundation may publish revised and/or new versions
of the General Public License from time to time. Such new versions will
be similar in spirit to the present version, but may differ in detail to
address new problems or concerns.
Each version is given a distinguishing version number. If the Program
specifies a version number of this License which applies to it and "any
later version", you have the option of following the terms and
conditions either of that version or of any later version published by
the Free Software Foundation. If the Program does not specify a version
number of this License, you may choose any version ever published by the
Free Software
Foundation.
10. If you wish to incorporate parts of the Program into other free
programs whose distribution conditions are different, write to the
author to ask for permission. For software which is copyrighted by the
Free Software Foundation, write to the Free Software Foundation; we
sometimes make exceptions for this. Our decision will be guided by the
two goals of preserving the free status of all derivatives of our free
software and of promoting the sharing and reuse of software generally.
[snip and end]
So "GPLv2" without a "+" or similar indeed seems to stand for
"GPLv2
only".
The GPL is v2 in the code as it's the same
one as coming from AMS.
As Ralf rightfully remarked, you have to check the original code for the
exact wording of the license. If it's GPLv2+ ("GPLv2 or later") you're
free to choose either GPLv2+ or GPLv3+, as the authors explicitly gave
you the permission to do that.
Unfortunately, the AMS manpage indeed seems to indicate that it is
licensed under GPLv2 only as the "or later" clause is missing there, and
I can't find any other statement in the latest released tarball or on
the website clarifying the license.
So your code probably needs to be licensed under GPLv2 only. GPLv2 is
still fine as a license (unless you're bothered by modern absurdities
like DRM, tivoization and software patents, that is). It poses a problem
if people want to use your code in their GPLv3+ projects, though -- they
can't.
So my interpretation is that if you'd like to relicense under GPLv3+
you'll have to contact Matthias Nagorni and get his explicit written
permission. According to the AMS manpage he's the only copyright holder
and I can't find any other copyright notices in the code, even though
there's no doubt that AMS has had a lot of contributions from Fons and
other people.
If I'm not mistaken, Matthias has long left for greener pastures,
though. Matthias, are you still lurking here? Maybe you can clarify the
license?
- I'm not even sure of what is the difference
between the version 2 and
the version 3 of the GPL.
There's plenty of information about that on the web. From the horse's
mouth: http://gplv3.fsf.org/rms-why.html.
- The code is ported from AMS. Am I aload to
change the license just
like that?
The license statement along with the license text tells you exactly what
you're allowed to do. In this case, as the "or later" clause is missing,
you're bound by the terms of the GPLv2, as set forth in the accompanying
COPYING file. Specifically, term 2 of the license tells you that you
have to relicense your derived work under the terms of the same license.
Disclaimer: IANAL either and this isn't legal advice, so when in doubt
consult your lawyer. ;-) But this is how I read the license terms of
AMS, to the best of my knowledge.
HTH,
Albert