AGPLv3 and GPLv2

[Luke Macken]

On Wed, Jun 10, 2009 at 04:17:57PM -0500, Mike McGrath wrote:
> So without knowing it we started using AGPLv3 code in our environment
> recently for fedora community and moksha.  In the past I think all of our
> stuff has been GPL(ish) mostly GPLv2 (toshio correct me if I'm wrong
> there)
> 
> I want to make sure we're all aware of what we can and can'd do as far as
> mixing the code between the two as this could be very unfortunate.
> 
> Luke, you described the AGPLv3 as "crucial".  Can you let the rest of us
> know why the GPLv2 wouldn't work?

Using GPLv2 would allow $BIG_EVIL_CORPORATION to take our code and run it
publicly on their servers without making the source available.  The AGPL fixes
this issue, which is known as the "application service provider loophole", and
would require them to put a link to the source code if one existed in the
original copy.  This is why you will see links to the Moksha and Fedora
Community source code at the bottom of every page.

I am not a lawyer, nor do I play one on television.  Someone smarter than I can
elaborate further, or correct any false assumptions that we have made.

More details from Wikipedia:

"""
Both versions of the AGPL were designed to close a perceived application
service provider "loophole" (the "ASP loophole") in the ordinary GPL, where by
using but not distributing the software, the copyleft provisions are not
triggered. Each version differs from the version of the GNU GPL on which it is
based in having an additional provision addressing use of software over a
computer network. The additional provision requires that the complete source
code be made available to any network user of the AGPL-licensed work, typically
a web application.

The Free Software Foundation has recommended that the GNU AGPLv3 be considered
for any software that will commonly be run over a network.[2] The Open Source
Initiative approved the GNU AGPLv3[3] as an Open Source license in March 2008
after Funambol submitted it for consideration[4]

[...]

Compatibility with the GPL

Both versions of the AGPL, like the corresponding versions of the GNU GPL on
which they are based, are strong copyleft licenses. In the FSF's judgment, the
additional requirement in section 2(d) of AGPLv1 made it incompatible with the
otherwise nearly identical GPLv2. That is to say, one cannot distribute a
single work formed by combining components covered by each license.

By contrast, GPLv3 and AGPLv3 each include clauses (in section 13 of each
license) that together achieve a form of mutual compatibility for the two
licenses. These clauses explicitly allow the "conveying" of a work formed by
linking code licensed under the one license against code licensed under the
other license.[7] In this way, the copyleft of each license is relaxed to allow
distribution of such combinations.  """

http://en.wikipedia.org/wiki/Affero_General_Public_License