Questions / Concepts GPL. Was: Re: GPL License with clause for Web use?

[Alex Hudson]

On Thu, 2007-11-22 at 13:52 +0000, Ciaran O'Riordan wrote:
> Alex Hudson <home at alexhudson.com> writes:
> >> Apache licence compatibility was achieved by allowing people to add the
> >> requirements of Apached licensed code to GPLv3 licensed code.
> >
> > Are you sure about that?
> 
> I'm certainly not an expert on this issue, but it looks like sections 4c and
> 4d of the AL have attribution requirements that aren't in GPLv3 and which
> make compatibility thus rely on the "additional requirements" provision of
> GPLv3's section 7b.  No?

I think you've answered your own question - it is in the GPLv3, in 7b :D

Section 7 enumerates some specific, limited, requirements that you can
supplement the GPLv3 with. The AGPL is treated completely specially:
there is no specific enumeration of the single requirement for a
web-quine.

That's the difference. Any additional restriction in the Apache license
must be matched by similar language in the GPLv3 for it to work. The
AGPL restriction, which has no such similar language in the GPLv3, only
works because the AGPL has preferential status. You can't add additional
restrictions beyond those the GPL sets out, unless you're the AGPL.

Cheers,

Alex.