Re: [Qemu-devel] An opinion on copyright-notice-less qemu files

[Richard Fontana]

On Wed, Oct 26, 2011 at 06:37:19PM -0500, Anthony Liguori wrote:

> >2) Because qemu has a LICENSE file (which, importantly, I am assuming
> >has been in place more or less from the get-go)
> 
> This is only sort of correct.  QEMU has been around since about
> 2003.  There has been a LICENSE file for all of it's significant
> history.
> 
> But for a long time period, QEMU contained no GPL code out side
> linux-user and LGPL code in libcpu.  The device model was strictly
> X11 licensed.  

Oops, I thought I had checked this ... then again I think I remember
the older LICENSE file from some earlier work...

> The old LICENSE file stated:
> 
> +The following points clarify the QEMU licenses:
> +
> +1) The QEMU virtual CPU core library (libqemu.a) and the QEMU PC
> +   system emulator are released under the GNU Lesser General Public
> +   License.
> +
> +2) The Linux user mode QEMU emulator is released under the GNU General
> +   Public License.
> +
> +3) The QEMU Accelerator Module is a proprietary product. It is
> +   available without charge. Commercial use of the QEMU Accelerator
> +   Module is allowed.
> +
> +   Redistribution of the QEMU Accelerator Module: any person or
> +   organisation wishing to distribute it, for example on a CD or as a
> +   binary or source package, must have an explicit authorization from
> +   the author.
> +
> +   The QEMU Accelerator Module is available without any express or
> +   implied warranty. In no event will the author be held liable for
> +   any damages arising from the use of this software.
> +
> +4) QEMU is a trademark of Fabrice Bellard.
> 
> Around 2007, a decision was made to allow GPL code in the system
> emulator.  At that point in time, the LICENSE text was clarified to
> it's current content (more or less).
> 
> A number of the pre-2007 files lack copyrights and where created
> before the "QEMU is overall licensed as GPL" text was added.
> 
> I don't think this necessarily changes your interpretation
> significantly but I thought its important to make this clarification
> at least.

Hmm, I don't think it affects the ultimate conclusion. I suppose this
suggests (if you buy into my general line of analysis) that there's
some noticeless pre-2007 code that arguably is more permissively
licensed than GPL (but GPL-compatible). In any such cases, however,
there's no issue at all. Some of the rhetorical points I made are
probably somewhat weakened by these additional facts. :)

What is interesting to me about the 2007 date is that is the year
GPLv3 was released, and in the months leading up to that time, and
thereafter, there was an increase in developer and corporate
consciousness about the significance of versionless or "or later" GPL
notices, yet the 2007 LICENSE file speaks of "the GNU General Public
License". I won't go so far as to suggest that that's significant in
any way other than what I've already said.

- RF