Debian Free Software Guidelines
Encyclopedia
The Debian Free Software Guidelines (DFSG) 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 the Debian Social Contract
.
and the primary authors were Bruce Perens
and several other Debian developers at the time.
The Open Source Definition
was created by modifying the text of the DFSG soon afterwards. DFSG was preceded by Free Software Foundation
's Free Software Definition
. 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 FSF's Free Software Definition existed as early as 1986, having been published in the first edition of the (now defunct) GNU's Bulletin. It is worth noting that the core of the Free Software Definition is the Four Freedoms, which clearly preceded the drafting and promulgation of the DFSG, but 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.
, 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:
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:
This prompted another General Resolution, 2004-004, in which the developers voted overwhelmingly against such action, and decided to postpone those changes until the next release (whose development started a year later, in June 2005).
, 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.
, 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.
The common tests (as described in the draft DFSG FAQ) are the following:
Debian
Debian is a computer operating system composed of software packages released as free and open source software primarily under the GNU General Public License along with other free software licenses. Debian GNU/Linux, which includes the GNU OS tools and Linux kernel, is a popular and influential...
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 the Debian Social Contract
Debian Social Contract
The Debian Social Contract is a document which frames the moral agenda of the Debian project. The values outlined in the Social Contract provide the basic principles for the rules set forth in the Debian Free Software Guidelines...
.
The guidelines
- Free redistribution.
- Inclusion of source code.
- Allowing for modifications and derived works.
- Integrity of the author's source code (as a compromise for the likes of TeXTeXTeX is a typesetting system designed and mostly written by Donald Knuth and released in 1978. Within the typesetting system, its name is formatted as ....
). - No discrimination against persons or groups.
- No discrimination against fields of endeavor, like commercial use.
- The license needs to apply to all to whom the program is redistributed.
- License must not be specific to Debian, basically a reiteration of the previous point.
- License must not contaminate other software.
- The GPLGNU General Public LicenseThe GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....
, BSD, and ArtisticArtistic LicenseThe Artistic License refers most commonly to the original Artistic License , a software license used for certain free and open source software packages, most notably the standard Perl implementation and most CPAN modules, which are dual-licensed under the Artistic License and the GNU General Public...
licenses are examples of licenses considered free.
History
The DFSG was first published together with the first version of the Debian Social Contract in July 1997. The concept of providing a formal guarantee for the distribution's licensing policy was suggested by Ean SchuesslerEan Schuessler
Ean Schuessler is co-founder, with his brother Erik Schuessler, of Brainfood, Inc., a Dallas, Texas-based digital media consultancy. He is a long-time participant in the Debian project and collaborated in the creation of the Debian Social Contract which inspired the Open Source Definition...
and the primary authors were Bruce Perens
Bruce Perens
Bruce Perens is a computer programmer and advocate in the open source community. He created the Open Source Definition and published the first formal announcement and manifesto of open source. He co-founded the Open Source Initiative with Eric S...
and several other Debian developers at the time.
The Open Source Definition
Open Source Definition
The Open Source Definition is a document published by the Open Source Initiative, to determine whether or not a software license can be labeled with the open-source certification mark....
was created by modifying the text of the DFSG soon afterwards. DFSG was preceded by Free Software Foundation
Free Software Foundation
The Free Software Foundation is a non-profit corporation founded by Richard Stallman on 4 October 1985 to support the free software movement, a copyleft-based movement which aims to promote the universal freedom to create, distribute and modify computer software...
's Free Software Definition
The Free Software Definition
The Free Software Definition, written by Richard Stallman and published by Free Software Foundation , defines free software, as a matter of liberty, not price. The term "free" is used in the sense of "free speech," not of "free beer." The earliest known publication of the definition was in the...
. Once the DFSG became the Open Source Definition
Open Source Definition
The Open Source Definition is a document published by the Open Source Initiative, to determine whether or not a software license can be labeled with the open-source certification mark....
, Richard Stallman
Richard Stallman
Richard Matthew Stallman , often shortened to rms,"'Richard Stallman' is just my mundane name; you can call me 'rms'"|last= Stallman|first= Richard|date= N.D.|work=Richard Stallman's homepage...
saw the need to differentiate Free Software
Free software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
from Open Source
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
and promoted the Free Software Definition. Published versions of FSF's Free Software Definition existed as early as 1986, having been published in the first edition of the (now defunct) GNU's Bulletin. It is worth noting that the core of the Free Software Definition is the Four Freedoms, which clearly preceded the drafting and promulgation of the DFSG, but were unknown to its authors.
In November 1998, Ian Jackson
Ian Jackson
Ian Jackson is a long time free software author and Debian developer. Jackson wrote dpkg, SAUCE, userv and debbugs. He used to maintain the Linux FAQ. He runs chiark.greenend.org.uk, a popular server, home to PuTTY among other things....
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.
, 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
Anthony Towns
Anthony Towns is a computer programmer who was a long-time Debian release manager, ftpmaster team member and later the Debian Project Leader...
, making a practical change:
- As [SC #1] 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 don't 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 such action, and decided to postpone those changes until the next release (whose development started a year later, in June 2005).
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.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 PostScriptPostScript
PostScript is a dynamically typed concatenative programming language created by John Warnock and Charles Geschke in 1982. It is best known for its use as a page description language in the electronic and desktop publishing areas. Adobe PostScript 3 is also the worldwide printing and imaging...
, 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
Software documentation
Software documentation or source code documentation is written text that accompanies computer software. It either explains how it operates or how to use it, and may mean different things to people in different roles....
, 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.
GFDL
Much documentation written by the GNU ProjectGNU Project
The GNU Project is a free software, mass collaboration project, announced on September 27, 1983, by Richard Stallman at MIT. It initiated GNU operating system development in January, 1984...
, the Linux Documentation Project
Linux Documentation Project
The Linux Documentation Project is an all-volunteer project that maintains a large collection of GNU and Linux-related documentation and publishes the collection online. It began as a way for hackers to share their documentation with each other and with their users, and for users to share...
and others licensed under the GNU Free Documentation License
GNU Free Documentation License
The GNU Free Documentation License is a copyleft license for free documentation, designed by the Free Software Foundation for the GNU Project. It is similar to the GNU General Public License, giving readers the rights to copy, redistribute, and modify a work and requires all copies and...
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.
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.debian-legal tests for DFSG compliance
The debian-legal mailing list subscribers have created some tests to check whether a license passes the DFSG.The common tests (as described in the draft DFSG FAQ) are the following:
- "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 dissidentDissidentA dissident, broadly defined, is a person who actively challenges an established doctrine, policy, or institution. When dissidents unite for a common cause they often effect a dissident movement....
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. - "The Tentacles of Evil test". Imagine that the author is hired by a large evil corporationEvil corporationAn evil corporation is a staple of science fiction , usually a big multinational company which values profits over ethics....
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.
See also
- The Free Software DefinitionThe Free Software DefinitionThe Free Software Definition, written by Richard Stallman and published by Free Software Foundation , defines free software, as a matter of liberty, not price. The term "free" is used in the sense of "free speech," not of "free beer." The earliest known publication of the definition was in the...
- History of free softwareHistory of free softwareThis is a timeline-style look at how free and open-source software has evolved and existed from its inception.The phrase "free software" refers to software that is liberally licensed, allowing the end user more freedoms than conventional-software licences. This is not to be confused with software...
External links
- Debian Social Contract and Free Software Guidelines
- debian-legal list, with archives from previous discussions
- Draft DFSG FAQ
- Section A.1.3 of Why OSS/FS? Look at the Numbers! identifies some of the major issues discussed by debian-legal.
- List of software licenses currently found in Debian