From: Ryan Pavlik <rpav@...>
Date: 2003-02-16T07:25:17+09:00
Subject: Re: GPL question

On Sun, 16 Feb 2003 06:59:11 +0900
Daniel Carrera <dcarrera@math.umd.edu> wrote:

> Hello,
> Suppose that I want to translate a Perl module into Ruby.  The Perl
> module is available under Perl's dual license: Artistic and GPL.

IANAL, but maybe the first question is whether this is a derived work as
defined under the GPL.  Are you just taking the API or specs and making
a Ruby module, or are you going more line by line?  Would even that
count as derived if you're rewriting it and not copying it literally? 
It seems the GPL only deals with actual cut and paste:

    2. You may modify your copy or copies of the Program or any portion
       of it, thus forming a work based on the Program, [...]

Further it says:

    These requirements apply to the modified work as a whole.  If
    identifiable sections of that work are not derived from the
    Program and can be reasonably considered independent and separate
    works in themselves, then this License, and its terms, do not
    apply to those sections when you distribute them as separate
    works. [...]

It doesn't seem to say anything about translation, but maybe I'm
missing something.

> Does that mean that I cannot release the Ruby version under Ruby's
> dual license?  Since Ruby's licenses don't include the Artistic, I
> would have to recive the module under the GPL.  But the GPL won't leat
> me relase the code under a dual license that includes the GPL.  Is
> that right?

I don't know what Ruby's license would have to do with this, except if
you derive your class from something GPL'd on the Ruby side.  But as
far as I understand the GPL, you can't relicense modified copies
(paragraph 2b says modified copies must be distributed "under the
terms of this License"), you can't impose additional restrictions on
the original work (paragraph 6).

This is mostly all beside the point, though.  If it's not a derived
work, it's yours, and you can do what you will (which will hopefully
include the GPL or LGPL).  Failing that, you could just ask the author
or authors.  They're the ones granting the license after all, and
they, not the GPL, own the work.

-- 
Ryan Pavlik <rpav@users.sf.net>

"Spinal hazards *are* hazardous..." - 8BT