Re: The invariant sections are not forbidden by DFSG
Anton Zinoviev wrote:
> Derived Works
> The license must allow modifications and derived works, and must allow
> them to be distributed under the same terms as the license of the
> original software.
> Notice that DFSG do not say "arbitrary modifications".
The general interpretation we've taken of this is "must allow modifications in
general, with restrictions allowable if they do not prevent reasonable use
"Invariant sections" prevent several reasonable use cases, which is why
they're generally considered non-free.
("Must allow X" is usually interpreted in law and ordinary English, IIRC, as
"must allow X in general". You could interpret it as "must allow at least
one X", but that's clearly not what the DFSG writers intended, and more
importantly, the "in general" interpretation is the normal interpretation of
> For example GPL says
> If the modified program normally reads commands interactively when
> run, you must cause it, when started running for such interactive
> use in the most ordinary way, to print or display an announcement
> including an appropriate copyright notice and a notice that there
> is no warranty (or else, saying that you provide a warranty) and
> that users may redistribute the program under these conditions, and
> telling the user how to view a copy of this License.
It's worth noting that many people consider this clause non-free, but it's
generally rendered free by the important line you omitted:
> (Exception: if the Program itself is interactive but does not normally print
such an announcement, your work based on the Program is not required to print
> If we want to decide whether some particular restrictions in the
> license make the license non-free or not, we have to use external to
> DFSG arguments. For example everybody is free to decide that the
> invariant sections make the document non-free but this can not be a
> consequence from DFSG.
Well, it's true that it can't be a pure, logical consequence. There is
*interpretation* (of the DFSG, of the Social Contract, of the license)
involved. It is not a matter totally separate from the DFSG either, however.
> My personal addition to DFSG is this: the license must allow us to
> improve the program and/or the documentation.
Ah. You've omitted an absolutely vital freedom, which the FSF seems to have
forgotten about when writing the GFDL: the freedom to adapt the work for
Many of us care very strongly about this freedom. This freedom is one of the
primary reasons why free software has been successful. Licenses which deny
or severely restrict this freedom must IMNSHO be considered non-free. The
major limits it places on this freedom are the fundamental practical reason
why the GFDL is a bad license.
Nathanael Nerode <firstname.lastname@example.org>
A thousand reasons. http://www.thousandreasons.org/
Lies, theft, war, kidnapping, torture, rape, murder...
Get me out of this fascist nightmare!