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Amendment: GFDL is compatible with DFSG

Hereby I am proposing an amendment to the GR about GFDL opened by
Anthony Towns [Sun, 01 Jan 2006 15:02:04 +1000]

I wish to thank everybody who will support this amendment, especially
I wish to thank those who second it.

I wish to thank also the members of the Debian mailing list at
lists.uni-sofia.bg, who assisted me with the text.

Anton Zinoviev


GNU Free Documentation License protects the freedom,
it is compatible with Debian Free Software Guidelines

(0) Summary

This is the position of Debian Project about the GNU Free
Documentation License as published by the Free Software Foundation:

   We consider that works licensed under GNU Free Documentation
   License version 1.2 do fully comply both with the requirements and
   the spirit of Debian Free Software Guidelines.

Within Debian community there has been a significant amount of
uncertainty about the GNU Free Documentation License (GFDL), and
whether it is, in fact, a "free" license.  This document attempts to
explain why Debian's answer is "yes".

(1) What is the GFDL?

The GFDL is a license written by the Free Software Foundation, who use
it as a license for their own documentation, and promote it to others. It
is also used as Wikipedia's license. To quote the GFDL's Preamble:

   The purpose of this License is to make a manual, textbook, or other
   functional and useful document "free" in the sense of freedom: to
   assure everyone the effective freedom to copy and redistribute it,
   with or without modifying it, either commercially or
   noncommercially. Secondarily, this License preserves for the author
   and publisher a way to get credit for their work, while not being
   considered responsible for modifications made by others.

   This License is a kind of "copyleft", which means that derivative
   works of the document must themselves be free in the same sense. It
   complements the GNU General Public License, which is a copyleft
   license designed for free software.

(2) The Invariant Sections - Main Objection Against GFDL

One of the most widespread objections against GFDL is that GFDL
permits works covered under it to include certain sections, designated
as "invariant".  The text inside such sections can not be changed or
removed from the work in future.

GFDL places considerable constraints on the purpose of texts that can
be included in an invariant section.  According to GFDL all invariant
sections must be also "secondary sections", i.e. they meet the
following definition

   A "Secondary Section" is a named appendix or a front-matter section
   of the Document that deals exclusively with the relationship of the
   publishers or authors of the Document to the Document's overall
   subject (or to related matters) and contains nothing that could
   fall directly within that overall subject. [...]  The relationship
   could be a matter of historical connection with the subject or with
   related matters, or of legal, commercial, philosophical, ethical or
   political position regarding them.

Consequently the secondary sections (and in particular the invariant
sections) are allowed to include only personal position of the authors
or the publishers to some subject.  It is useless and unethical to
modify somebody else's personal position; in some cases this is even
illegal.  For such texts Richard Stallman (the founder of the Free
Software Movement and the GNU project and author of GFDL) says [1]:

   The whole point of those works is that they tell you what somebody
   thinks or what somebody saw or what somebody believes. To modify
   them is to misrepresent the authors; so modifying these works is
   not a socially useful activity. And so verbatim copying is the only
   thing that people really need to be allowed to do.

This feature of GFDL can be opposed to the following requirement of
Debian Free Software Guidelines:

   3. 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.

It is naive to think that in order to fulfil this requirement of DFSG
the free licenses have to permit arbitrary modifications.  There are
several licenses that Debian has always acknowledged as free that
impose some limitations on the permitted modifications.  For example
the GNU General Public License contains the following clause:

   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.

The licenses that contain the so called "advertising clause" give us
another example:

   All advertising materials mentioning features or use of this
   software must display the following acknowledgement: "This product
   includes software developed by ..."

Consequently when judging whether some license is free or not, one has
to take into account what kind of restrictions are imposed and how
these restrictions fit to the Social Contract of Debian:

   4. Our priorities are our users and free software

   We will be guided by the needs of our users and the free software
   community.  We will place their interests first in our priorities.

Currently GFDL is a license acknowledged as free by the great mass of
the members of the free software community and as a result it is used
for the documentation of great part of the currently available free
programs.  If Debian decided that GFDL is not free, this would mean
that Debian attempted to impose on the free software community
alternative meaning of "free software", effectively violating its
Social Contract with the free software community.

We should be able to improve the free software and to adapt it to
certain needs and this stays behind the requirement of DFSG for
modifiability.  GFDL allows everybody who disagrees with a personal
position expressed in an invariant section to add their own secondary
section and to describe their objections or additions.  This is a
reasonable method to improve the available secondary sections, a
method that does not lead to misrepresenting the authors opinion or to

(3) Transparent copies

Another objections against GFDL is that according to GFDL it is not
enough to just put a transparent copy of a document alongside with the
opaque version when you are distributing it (which is all that you
need to do for sources under the GPL, for example). Instead, the GFDL
insists that you must somehow include a machine-readable Transparent
copy (i.e., not allow the opaque form to be downloaded without the
transparent form) or keep the transparent form available for download
at a publicly accessible location for one year after the last
distribution of the opaque form.

The following is what the license says (the capitalisations are not
from the original license):

   You must either include a machine-readable Transparent copy ALONG
   with each Opaque copy, or state IN OR WITH each Opaque copy a
   computer-network location from which the general network-using
   public has access to download using public-standard network
   protocols a complete Transparent copy of the Document, free of
   added material.

Consequently the license requires distribution of the transparent form
ALONG with each opaque copy but not IN OR WITH each opaque copy.  It
is a fact confirmed by Richard Stallman, author of GFDL, and testified
by the common practice, that as long as you make the source and
binaries available so that the users can see what's available and take
what they want, you have done what is required of you.  It is up to
the user whether to download the transparent form.

If the transparent copy is not distributed along with the opaque copy
then one must take reasonably prudent steps to ensure that the
Transparent copy will remain accessible from Internet at a stated
location until at least one year.  In these curcumstances the
requirement of GPL appears to be even more severe - a written offer,
valid for at least three years, to give any third party a complete
machine-readable copy of the corresponding source code.

(4) Digital Rights Management

The third objection against GFDL arises from the measures in Section 2
that attempt to overcome Digital Rights Management (DRM) technologies.
According to some interpretations of the license, it rules out
distributing copies on DRM-protected media, even if done in such a way
as to give users full access to a transparent copy of the work; and,
as written, it also potentially disallows encrypting the
documentation, or even storing it on a file system that supports

In fact, the license says only this:

   You may not use technical measures to obstruct or control the
   reading or further copying of the copies you make or distribute

This clause disallows the distribution or storage of copies on
DRM-protected media only if a result of that action will be that the
reading or further copying of the copies is obstructed or controlled.
It is not supposed to refer the use of encryption or file access
control on your own copy.

Consequently the measures of the license against the DRM technologies
are only a way to ensure that the users are able to exercise the
rights they should have according to the license.  Because of that,
these measures serve similar purpose to the measures taken in the GNU
General Public License against the patents:

   If a patent license would not permit royalty-free redistribution of
   the Program by all those who receive copies directly or indirectly
   through you, then the only way you could satisfy both it and this
   License would be to refrain entirely from distribution of the

We do not think that this requirement of GPL makes GPL covered
programs non-free even though it can potentially make a GPL-covered
program undistributable.  Its purpose is against misuse of patents.
Similarly, we do not think that GFDL covered documentation is non-free
because of the measures taken in the license against misuse of
DRM-protected media.

[1] http://www.gnu.org/philosophy/copyright-and-globalization.html
[2] http://www.gnu.org/doc/gnupresspub.html

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