Subject:
Re: [discuss] licence problems
From:
Rick Moen ####@####.####
Date:
25 Sep 2008 19:43:40 +0100
Message-Id: <20080925184337.GH13340@linuxmafia.com>
Quoting Jean-Daniel Dodin ####@####.####
> Andrew M.A. Cater a écrit :
>
> > Please note: unless they are GFDL with no invariant sections - they
> > won't ever go anywhere near Debian.
>
> it's that what is wanted at the time.
>
> I copy here a trhread that I started inadvertently elsewhere, but is
> better here
>
> Rick Moen a écrit :
>
> >> could there be any advantage to default LDP doc to dual licences
> >> (apart making lawyers rich?)
> >
> > Of course there is.
> >
> > First of all, the author giving people additional permissions cannot
> > possibly make any author rich. If you don't mind my saying so, your
> > question suggests you're confusing dual-licensing -- giving the
> > recipient the choice of two alternative licences -- with the use of two
> > incompatible licences within a single work.
>
> no.
>
> but you can have a situation where two derivative works have twxo
> uncompatible licences, and how do you cope with this on the LDP?
I'm not sure I understand your phrase "a situation where two derivative
works have two incompatible licences". Let's attempt to discuss a
specific situation.
Let's say I put document A on the Web, with a copyright statement that
says, as a permissive licence:
Copyright (C) 2008 Rick Moen. Do whatever you want with this work,
provided you agree that I make no warranty of any kind.
A year later, someone uses that to create and post derivative work B,
which he licences as follows:
Copyright (C) 2008-2009 Blue Guy and Rick Moen. People whose favourite
colour is blue may do anything they want with this work, provided
they agree that Rick Moen makes no warranty of any kind.
(Creation and distribution of this derivative work is permitted by my
licence.) Meanwhile, someone else writes and posts derivative work C,
which he licences as follows:
Copyright (C) 2008-2009 Green Guy and Rick Moen. People whose favourite
colour is green may do anything they want with this work, provided
they agree that Rick Moen makes no warranty of any kind.
This work's creation and distribution is likewise permitted by my
licence.
Works B and C have incompatible licences, in the sense that a fourth
party cannot lawfully create and distribute work D that borrows from
both works B and C (because their conditions of use cannot be satisfied
simultaneously), without an additional grant of permission from either
Green Guy or Blue Guy.
How "do you cope with this on the LDP"? LDP can accept works A, B, or
C, with no problems. It cannot accept work D, because its licence
conditions cannot be satisfied.
I hope that example is of some use. (I'm not proposing that any of the
above licences be regarded as "reasonable" by LDP, by the way,
completely aside from the reference to favourite colours being whimsical
;-> -- though some folks might in the future want to give LDP works
licensed like document _A_, and it's a scenario worth pondering.)
Anyway, my main point was that _dual_ licensing specifies the _union_
(disjoint set) of two licences: The recepient need satisfy only one, of
them, either one. By contrast, a single work with portions under two
licences requires that users satisfy the _intersection_ (cross set) of
the licences. The user must comply with _both_ licences, or else is
committing copyright violation if he/she redistributes the work or
creates/distributes a derivative of it.
> if one author changes the beginning of the document and an other the
> end of it?
You seem, here, to be talking about something like document D, from the
example above -- where licensing requires that the user's favourite
colour be green _and_ simultaneously requires that the user's favourite
colour be blue. LDP should not accept documents with conflicting
licence terms, as its conditions for users' gaining permission to
redistribute or create derivative works cannot be satisfied, and
therefore it becomes in effect a work under a non-free licence.
Please note that this is _not_ dual-licensing! This is the oppposite
of dual-licensing -- requiring satisfaction of the intersection of two
licences, rather than their union set.
> and if the authors feel confident with GPL and not with GFDL, I don't
> see how tha dual licencing can make them glad.
I suspect the problem is that you are persisting in not understanding
what dual licensing _is_.
Again, here is a real-world example of dual licensing:
http://tldp.org/FAQ/WordPerfect-Linux-FAQ/feedback.html
Any recipient may lawfully redistribute and/or modify the work if he/she
satisifes the conditions of _either_ GPLv2 _or_ CC BY-SA 2.0 or above.
Clearer?
> After all one can say: "do whatever you want of my doc", or don't say
> anything and so keep all the rights, so any licence goal is to give
> some rights, but not all and dual licencing only makes it more
> difficult to understand.
Please have a look at
http://tldp.org/FAQ/WordPerfect-Linux-FAQ/feedback.html and tell me
honestly that "you may accept this work under _either_ GPLv2 or CC BY-SA
2.0 or later" is difficult to understand.
You might wonder how that document came to be dual-licensed.
Fortunately, as author, I'm in a position to explain. ;->
When I wrote the initial versions, GPLv2 was one of the best and most
obvious choices for a reciprocal (copyleft) documentation licences.
A few years later, Creative Commons got started, and I gradually became
convinced that its two free licences -- BY, which is permissive, and
BY-SA, which is copyleft) had real advantages. For one thing, a BY-SA
document can be published in a book without having to include "source
code" (preferred form) or a written offer to furnish it good for three
years.
I _could_ have just specified only BY-SA for newer FAQ releases -- but I
reasoned, "Why should I withdraw the GPLv2 permission for readers who
prefer it?" So, I let readers accept under _either_ licence.
> oh yes, I have!
OK, good.
> and I don't care of the default LDP licence, but to say we must have
> one allowing derivative works to be able to change content and even
> authors.
Right. The default LDP licence was always a strategic error.
