On Wed, 25 Jan 2006, Chase Venters wrote:
This means that when the code went GPL v1 -> GPL v2, the transition was
permissible. Linux v1.0 shipped with the GPL v2. It did not ship with a
separate clause specifying that "You may only use *this* version of the GPL"
as it now does. (I haven't done any research to find out when this clause was
added, but it was after the transition to v2).
Bzzt. Look closer.
The Linux kernel has _always_ been under the GPL v2. Nothing else has ever
been valid.
The original GPL said something about:
"You may not impose any further restrictions on the recipients'
exercise of the rights granted herein." (Section 6).
Then, that __exact__ code was redistributed under Version 2
which further restricted rights,
The "version 2 of the License, or (at your option) any later version"
language in the GPL copying file is not - and has never been - part of the
actual License itself. It's part of the _explanatory_ text that talks
about how to apply the license to your program, and it says that _if_ you
want to accept any later versions of the GPL, you can state so in your
source code.
The Linux kernel has never stated that in general. Some authors have
chosen to use the suggested FSF boilerplate (including the "any later
version" language), but the kernel in general never has.
In other words: the _default_ license strategy is always just the
particular version of the GPL that accompanies a project. If you want to
license a program under _any_ later version of the GPL, you have to state
so explicitly. Linux never did.
So: the extra blurb at the top of the COPYING file in the kernel source
tree was added not to _change_ the license, but to _clarify_ these points
so that there wouldn't be any confusion.
The Linux kernel is under the GPL version 2. Not anything else. Some
individual files are licenceable under v3, but not the kernel in general.
And quite frankly, I don't see that changing. I think it's insane to
require people to make their private signing keys available, for example.
I wouldn't do it. So I don't think the GPL v3 conversion is going to
happen for the kernel, since I personally don't want to convert any of my
code.