Re: Affero General Public License
Nathanael Nerode wrote:
Florian Weimer wrote:
It seems that web.py does not include the source transmission facility
mentioned in the AGPL. As a result, the additional clause is void,
and the license should be DFSG-free.
Unfortunately the clause is not void.
(1) This is a copyleft, so all derivative works must use the same license;
(2) unlike clause 2c which applies if the *modified* program satisfies certain
conditions, clause 2d applies if the "Program as you received it" satisfies
So if I create a derivative work of web.py ("webplus.py") which *does* include
the facility mentioned in the AGPL, no subsequent derivative works of
"webplus.py" can ever remove it. This regardless of *my* desires as the
author of the source transmisison facility!
This is pretty hideous. I don't know if it's non-free, but I'd guess so.
Is there a way around it? Dual-licensing my portions of "webplus.py" under a
free license, and then distributing only in patch form (so that the
recipients never receive "webplus.py" as a single work)? No, that wouldn't
allow binary distribution.
It seems yes however. If you distribute the source in that way, then the
users having received the source have received a copy of the unmodified
source code (i.e. he has then received a copy of the software not
containing that facility). He can then modify this source code without
including the facility. The fact that he has previously received a
binary containg the facility does not seems to change anything (since he
modifies the source code, not the binary).
Anyway, I am not sure that the interpretation of the AGPL given on this
list is the exact one. It seems reasonable to interpret it as "if the
software interact with the user, this facility must be preserved") (it
is in the spirit of the license). I agree however that this unclear; and
I think it is worthwhile to ask clarification to the upstream authors.