----- Original Message -----
From: "Dan Collins"
<dcollin1(a)stevens.edu>
On Fri, Dec 30, 2011 at 9:15 AM, Jay Ashworth
<jra(a)baylink.com> wrote:
----- Original Message -----
From: "Tim Starling"
<tstarling(a)wikimedia.org>
On 30/12/11 08:30, Dan Collins wrote:
On Thu, Dec 29, 2011 at 4:24 PM, Huib Laurens
<sterkebak(a)gmail.com>
wrote:
> It doesn't need to be compatible or open-source right?
GPL 2.0 section 2 b:
b) You must cause any work that you distribute or publish, that
in
whole or in part contains or is derived from the Program or any
part
thereof, to be licensed as a whole at no charge to all third
parties
under the terms of this License.
You can modify GPL software for private use. That clause only kicks
in
when you "distribute or publish" the work, so you're generally OK
if
you're just using it within a single company. Maybe that's what
Huib
meant by "closed source".
And since we're not under the *Affero* GPL, you can modify it, *and
make it
publicly available*, and still not be constrained by the licence (I
don't
think I've got that backwards, do I?)
You may be slightly confused or I may be slightly not a lawyer, but:
The Affero licence states that you may not use, distribute, or publish
any licensed or derivative work under any other licence.
The vanilla GPL states that you may not distribute or publish licensed
or derivative work under any other licence.
It is therefore acceptable for Big Business Inc. to modify MediaWiki
and **use** it as
bigbusiness.com, however they may not sell or give
(**distribute**) their modified version to any other company or
individual unless they obey the terms of the License. So if whoever it
is decided to modify MediaWiki by adding a closed-source extension,
however that works, and then gave that to their customers to put on
their websites, then they have violated the GPL, because they must
make available the complete source of their **derivative work** which
they have **distributed**. If however they have decided to modify
MediaWiki by adding a closed-source extension, however that works, and
then placed that on their servers at the request of a customer, then
they have not violated the GPL because their derivative work is being
**used** but not distributed.
This sort of thing gets complicated when you think about things like
paid hosting - you're selling it and making it available for use but
not distributing it. You'd think that they're breaking some provision
by making money off of their modified MediaWiki but I'm pretty sure
they aren't as long as the derivative work stays on their servers.
(but is the HTML generated then also a derivative work? probably not?)
Ok, ok, I'll go look. :-)
Yeah, I was right.
That's what the AGPL does: it makes it a violation of license to make non-
public changes to a GPLd app, *and then make it available as a webservice,
without physically distributing the code*.
The GPL proper does not prevent that, which is the topic we're discussing
here: since the MediaWiki code is not under AGPL, you can modify it, not
release your mods, *and run it on your own web service*, and not violate
the license.
If you distribute it outside your organization in such a fashion, though,
*that* trips the traditional GPL.
Cheers,
-- jra
--
Jay R. Ashworth Baylink jra(a)baylink.com
Designer The Things I Think RFC 2100
Ashworth & Associates
http://baylink.pitas.com 2000 Land Rover DII
St Petersburg FL USA
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