ⓘ Debian Free Software Guidelines


ⓘ Debian Free Software Guidelines

The Debian Free Software Guidelines is a set of guidelines that the Debian Project uses to determine whether a software license is a free software license, which in turn is used to determine whether a piece of software can be included in Debian. The DFSG is part of th.


1. The guidelines

  • No discrimination against persons or groups.
  • No discrimination against fields of endeavor, like commercial use.
  • Integrity of the authors source code as a compromise.
  • License must not be specific to a product.
  • Free redistribution.
  • Inclusion of source code.
  • The license needs to apply to all to whom the program is redistributed.
  • Allowing for modifications and derived works.
  • License must not restrict other software.

The GNU GPL, BSD, and Artistic licenses are examples of licenses considered free.


2. History

The DFSG was first published together with the first version of the Debian Social Contract in July 1997. The primary author was Bruce Perens, with input from the Debian developers during a month-long discussion on a private mailing list, as part of the larger Debian Social Contract. Perens was copied to an email discussion between Ean Schuessler then of Debian and Donnie Barnes of Red Hat, in which Schuessler accused Red Hat of never elucidating its social contract with the Linux community. Perens realized that neither did Debian have any formal social contract, and immediately started creating one.

The Open Source Definition was created by re-titling the exact text of the DFSG soon afterwards. DFSG was preceded by Free Software Foundations Free Software Definition, which then defined three freedoms of Free Software Freedom Zero was added later, but this text was not used in the creation of the DFSG. Once the DFSG became the Open Source Definition, Richard Stallman saw the need to differentiate free software from open source and promoted the Free Software Definition. Published versions of FSFs Free Software Definition existed as early as 1986, having been published in the first edition of the now defunct GNUs Bulletin. It is worth noting that the core of the Free Software Definition was the then Three Freedoms, which clearly preceded the drafting and promulgation of the DFSG, were unknown to its authors.

In November 1998, Ian Jackson and others proposed several changes in a draft versioned 1.4, but the changes were never made official. Jackson stated that the problems were "loose wording" and the patch clause.

As of 2011, the document has never been revised. Nevertheless, there were changes made to the Social Contract which were considered to affect the parts of the distribution covered by the DFSG.

The Debian General Resolution 2004-003, titled "Editorial amendments to the social contract", modified the Social Contract. The proposer Andrew Suffield stated:

"The rule is this resolution only changes the letter of the law, not the spirit. Mostly it changes the wording of the social contract to better reflect what it is supposed to mean, and this is mostly in light of issues that were not considered when it was originally written."

However, the change of the sentence "We promise to keep the Debian GNU/Linux Distribution entirely free software" into "We promise that the Debian system and all its components will be free" resulted in the release manager, Anthony Towns, making a practical change:

"As is no longer limited to software, and as this decision was made by developers after and during discussion of how we should consider non-software content such as documentation and firmware, I dont believe I can justify the policy decisions to exempt documentation, firmware, or content any longer, as the Social Contract has been amended to cover all these areas."

This prompted another General Resolution, 2004-004, in which the developers voted overwhelmingly against immediate action, and decided to postpone those changes until the next release whose development started a year later, in June 2005.


3.1. Application Software

Most discussions about the DFSG happen on the debian-legal mailing list. When a Debian Developer first uploads a package for inclusion in Debian, the ftpmaster team checks the software licenses and determines whether they are in accordance with the social contract. The team sometimes confers with the debian-legal list in difficult cases.


3.2. Application Non-"software" content

The DFSG is focused on software, but the word itself is unclear - some apply it to everything that can be expressed as a stream of bits, while a minority considers it to refer to just computer programs. Also, the existence of PostScript, executable scripts, sourced documents, etc., greatly muddies the second definition. Thus, to break the confusion, in June 2004 the Debian project decided to explicitly apply the same principles to software documentation, multimedia data and other content. The non-program content of Debian began to comply with the DFSG more strictly in Debian 4.0 released in April 2007 and subsequent releases.


3.3. Application GFDL

Much documentation written by the GNU Project, the Linux Documentation Project and others licensed under the GNU Free Documentation License contain invariant sections, which do not comply with the DFSG. This assertion is the end result of a long discussion and the General Resolution 2006-001.

Due to the GFDL invariant sections, content under this license must be separately contained in an additional "non-free" repository which is not officially considered part of Debian.


3.4. Application Multimedia files

It can be sometimes hard to define what constitutes the "source" for multimedia files, such as whether an uncompressed image file is the source of a compressed image and whether the 3D model before ray tracing is the source for its resulting image.


4. debian-legal tests for DFSG compliance

The debian-legal mailing list subscribers have created some tests to check whether a license violates the DFSG. The common tests as described in the draft DFSG FAQ are the following:

  • "The Tentacles of Evil test". Imagine that the author is hired by a large evil corporation and, now in their thrall, attempts to do the worst to the users of the program: to make their lives miserable, to make them stop using the program, to expose them to legal liability, to make the program non-free, to discover their secrets, etc. The same can happen to a corporation bought out by a larger corporation bent on destroying free software in order to maintain its monopoly and extend its evil empire. To be free, the license cannot allow even the author to take away the required freedoms.
  • "The Desert Island test". Imagine a castaway on a desert island with a solar-powered computer. This would make it impossible to fulfill any requirement to make changes publicly available or to send patches to some particular place. This holds even if such requirements are only upon request, as the castaway might be able to receive messages but be unable to send them. To be free, software must be modifiable by this unfortunate castaway, who must also be able to legally share modifications with friends on the island.
  • "The Dissident test". Consider a dissident in a totalitarian state who wishes to share a modified bit of software with fellow dissidents, but does not wish to reveal the identity of the modifier, or directly reveal the modifications themselves, or even possession of the program, to the government. Any requirement for sending source modifications to anyone other than the recipient of the modified binary - in fact, any forced distribution at all, beyond giving source to those who receive a copy of the binary - would put the dissident in danger. For Debian to consider software free it must not require any such excess distribution.

  • unofficial builds. The Debian Free Software Guidelines are used by the Debian project to determine whether a license is a free license, which in turn
  • Debian Project Leader and three foundational documents: the Debian Social Contract, the Debian Constitution, and the Debian Free Software Guidelines
  • for the Debian Free Software Guidelines that serve as the basis of the Open Source Definition. Debian believes the makers of a free software operating
  • Free Cultural Works Debian Free Software Guidelines The Open Source Definition What is free software - GNU Project - Free Software Foundation Gnu.org
  • free and open - source software licenses Contributor License Agreement Copyleft Debian Free Software Guidelines Definition of Free Cultural Works Free license
  • The Debian project uses the criteria laid out in its Debian Free Software Guidelines DFSG The only notable cases where Debian and Free Software Foundation
  • definitions that describe an almost identical set of software The most notable are Debian Free Software Guidelines published in 1997, and the Open Source Definition
  • agreed not to be too problematic for Debian to distribute but does not meet the Debian Free Software Guidelines and therefore cannot be included in their
  • efforts of sustaining a software ecosystem for their field The Debian 8 Jessie release consists of approximately 43, 000 software packages. Therefore, without
  • for different domains in Free Software Definition, Open Source Definition, Debian Free Software Guidelines Definition of Free Cultural Works and The Open
  • Free and open - source software portal Anaconda Calamares Ubiquity Wubi Debian stretch Release Information Debian Retrieved 2015 - 04 - 27. Debian GNU Linux