Subject: RE: GNU GPL "any later version" question
From: "Wilson, Andrew" <andrew.wilson@intel.com>
Date: Mon, 15 Aug 2005 10:53:14 -0700

 Mon, 15 Aug 2005 10:53:14 -0700

James Bennett wrote: 

> Now, I may be completely wrong, and indeed would love to be completely
> wrong and to know why I'm completely wrong, but the impression I get
is
> that in item 5 above I have violated the terms of GPLv2 (Section 6),
by
> distributing the program or a derivative work with restrictions which
> aren't present in GPLv2. The GPL FAQ isn't particularly helpful here;
> its most relevant point is this:
>
>> But if the new GPL version has a tighter requirement, it will not
>> restrict use of the current version of the program, because it can
>> still be used under GPL version 2. When a program says "Version 2 of
>> the GPL or any later version", users will always be permitted to use 
>> it, and even change it, according to the terms of GPL version 2--even
>> after later versions of the GPL are available.
>
> This merely points out the obvious, which is that people I distribute
to
> are still free to choose GPLv2 as an option.

As in so much about the GPL, I'm not sure this is really so obvious.
This is stating the FSF's assertion that the dual-license-ness of code
licensed under GPL v2 "or any later version" persists throughout the
distribution chain, forever.  If you accept this assertion, then it
doesn't matter if I make a distribution to you of GPL code which 
I accepted under v3; you still have the "freedom" to accept such 
code under the Ts and Cs of v2.

Persistent dual licensing is not a universal norm.  There are other
multi-licensing regimes in open source projects
where the recipient is allowed to make a
choice of license, and then stick to it.  For example, the suggested
verbiage for triple-licensing Mozilla code MPL/GPL/LGPL
(see http://www.mozilla.org/MPL/boilerplate-1.1/mpl-tri-license-txt)
allows you to indicate that you elect to accept the code only under
GPL/LGPL by simply removing all language referring to MPL.
Downstream from someone who has made such an election, use under MPL
is presumably not allowed.

> Could someone with stronger license-fu than myself please shed some
> light on this?

When v3 comes out, the vast amount of code licensed under v2
"or any later version" will instantly become dual-licensed.  We will
all have to get schooled quickly on the finer points of dual licensing.

Andy Wilson
Intel Open Source Technology Center