The DFSG and Software Licenses
This page is designed to be a first stop if you're making a new package and are not sure about whether its license allows it to meet the DebianFreeSoftwareGuidelines. Feel free to add licenses, with a link to their text and -- if possible -- a link to a related message in the DebianLegal archive. There is a licenses page on Debian's website too now: http://www.debian.org/legal/licenses/
Some of the licenses listed here are linked to the http://opensource.org/ site. If you find a link to the license on the original site, feel free to change it.
Please be aware that this page is not definitive and is intended to be an informational summary for packagers. http://www.debian.org/legal/licenses/ is somewhat more definitive, but is still not comprehensive. Licenses may be listed here that are not listed there, and vice versa. The decision on what licenses are acceptable is normally taken by the ftp team after project discussion, and may be the subject of project General Resolutions, but in most cases the presence of the license in the archive is the best indication that it's acceptable. There is not, at present, any completely definitive list of what licenses Debian does or does not accept.
The sections on this page are:
The DFSG and Software Licenses
The Big DFSG-compatible Licenses
- The GNU General Public License (GPL)
- The GNU Lesser General Public License (LGPL)
- The Apache Software License (ASL)
- Mozilla Public License (MPL)
- The 3-clause BSD License
- The Artistic License
- The MIT License
- The Open Font License
- Creative Commons Attribution Share-Alike (CC-BY-SA) v4.0
- Creative Commons Attribution Share-Alike (CC-BY-SA) v3.0
- Common Public License (CPL), Version 1.0
- IBM Public License, Version 1.0
- Other DFSG compatible licenses
- Licenses whose status is unsettled
Licenses that are DFSG-incompatible
- Apple Public Source License (APSL)
- GNU Free Documentation License (GFDL)
- Open Publication License (OPL) v1.0
- Open Software License (OSL) v1.1
- Creative Commons Attribution License (CC-by), v1.0
- Creative Commons Attribution-Non Commercial-Share Alike (CC-by-nc-sa)
- Creative Commons Attribution-Share Alike Generic (CC-BY-SA), v1.0
- Creative Commons Sampling Plus (CC-sampling+), v1.0
- JSON evil license
- License for OpenPBS and Torque
- Swiss Ephemeris Public License
- RealNetworks Public Source License (RPSL)
- SPIN License
- Common Public Attribution License
- More Resources
- The Big DFSG-compatible Licenses
The Big DFSG-compatible Licenses
We consider a "big license" to be well known and either widely used, or used by very important projects.
The GNU General Public License (GPL)
This is the most popular free software license. Most of Linux (the kernel) is distributed under the GPL, as is most of the other basic software in the GNU operating system.
The GNU Lesser General Public License (LGPL)
(Earlier called the "Library General Public License"; this name is deprecated because it confuses the license's intent.)
The GNU C library is distributed under the LGPL.
The Apache Software License (ASL)
The Apache web server is distributed under the ASL. The current version of the ASL is 2.0.
Older versions of the Apache License (1.0 and 1.1) are also DFSG free, but the Apache Software Foundation recommends using the Apache 2.0 license instead.
Mozilla Public License (MPL)
The MPL is a DFSG-free license, which is suitable for Debian main. http://lists.debian.org/debian-legal/2007/07/msg00197.html http://lists.debian.org/debian-legal/2007/07/msg00215.html
The 3-clause BSD License
(This is distinct from the original, 4-clause BSD license that included an advertising requirement. The original license is now deprecated even by the BSD project.)
The BSD operating system, and many utilities that come from it, are licensed under the 3-clause BSD license.
Note that a 2-clause form of the BSD license, removing the third condition, is also in use. This is because even a generous copyright license does not implicitly forfeit the copyright holder's "right of publicity". In other words, even if a license does not forbid you from claiming that the copyright holder or other parties endorses or promotes your work, the law generally does. We're not aware of any exceptions.
The Artistic License
Perl is licensed under the Artistic License.
Do note that the Artistic License is considered non-free by the FSF. They suggest to use the Clarified Artistic License (also called Artistic License 2.0) instead. However, the original Artistic License is still considered DFSG-free.
The MIT License
The shortest one. Learn it by heart if you write a lot of scripts
Most of the X Window System is distributed under the MIT License.
Exception : The University of Washington's interpretation of the MIT License, as the University interprets it for the pine email client, does not follow the DFSG. See the DebianFreeSoftwareGuidelinesDraftFAQ.
pine is not part of Debian.
The Open Font License
The following restriction on distributions, which is part of OFL, has been widely accepted by open source projects when it is applied to fonts:
- 1) Neither the Font Software nor any of its individual components, in Original or Modified Versions, may be sold by itself.
Creative Commons Attribution Share-Alike (CC-BY-SA) v4.0
Version 4.0 is considered to be compatible to the DFSG. Changes from the previous version are discussed in a thread starting at https://lists.debian.org/3172728.oiOx47Q9HF@debstor
Creative Commons Attribution Share-Alike (CC-BY-SA) v3.0
In contrast to the CC-SA 1.0 license, version 3.0 is considered to be compatible to the DFSG. In addition, the version 2.0 and 2.5 are NOT transitively compatible because of clause 4b, since that only allows redistribution of derivative works under later versions of the license.
Common Public License (CPL), Version 1.0
IBM's CPL FAQ http://www.ibm.com/developerworks/library/os-cplfaq/
Discussion on debian-legal http://lists.debian.org/debian-legal/2001/debian-legal-200112/msg00144.html
See the IBM Public License, immediately below.
IBM Public License, Version 1.0
License Text http://www.opensource.org/licenses/ibmpl.php
Discussion on debian-legal http://lists.debian.org/debian-legal/1999/debian-legal-199906/msg00234.html
This license was later renamed the Common Public License (CPL). It is used for OpenAFS and Postfix and has been accepted in Debian main since 2000.
Other DFSG compatible licenses
Internet Systems Consortium License Text https://spdx.org/licenses/ISC
- Software released under it is cleared by Debian FTP masters.
Discussion and resolution on debian-legal https://lists.debian.org/debian-legal/2016/10/threads.html
The MirOS Licence
Licenses whose status is unsettled
Works under licenses in this group are not (yet?) accepted into debian main. This may change.
Q Public License (QPL), Version 1.0
License Text http://www.trolltech.com/licenses/qpl.html
Discussion on debian-legal http://lists.debian.org/debian-legal/2003/debian-legal-200303/msg00459.html http://lists.debian.org/debian-legal/2004/debian-legal-200404/msg00233.html http://lists.debian.org/debian-legal/2004/06/msg00131.html
Relevant additional info 251983
The DFSG-freeness of this license has been called into question. Some people appear to believe that because the Qt library is in Debian main, that the QPL is DFSG-free. That is a hasty conclusion, however, because the Qt library is also licensed under the GNU GPL (see http://www.trolltech.com/newsroom/announcements/00000043.html).
The QPL is not GPL-compatible, which, regardless of one's opinion about the license's DFSG-freeness, poses a major practical problem for any code licensed under the QPL that is reused elsewhere in conjunction with code under the GNU GPL. This makes the QPL alone a particularly poor choice of license for a library.
Furthermore, it is not clear that the Trolltech corporation (the author of the Qt library and the QPL itself) believes the QPL to be a free software license. Trolltech's website describes how their dual-license approach is intended to be "open source-friendly" (see http://www.trolltech.com/company/model.html). If Trolltech felt that the QPL alone were friendly enough to open-source, why do they have a dual-licensing policy?
Copyright holders in QPL-licensed works should be encouraged to follow Trolltech's example, and dual-license their work under the GNU GPL or another clearly DFSG-free license.
Status on debian-legal: http://lists.debian.org/debian-legal/2004/debian-legal-200403/msg00340.html
Only used by X-Oz Technologies, Inc.
This license's acceptance is stalled waiting for answers from a representative of X-Oz Technologies, Inc since April 2004.
Licence Art Libre (Free Art License)
Text (French original): http://artlibre.org/licence/lal
Text (English translation): http://artlibre.org/licence/lal/en
Might not pass DissidentTest. Problems in the translation slow down approval to a halt.
Discussion January 2011 on debian-legal: http://lists.debian.org/debian-legal/2011/01/msg00042.html
Licenses that are DFSG-incompatible
These licenses seem impossible to use in a way that follows DFSG without significant exceptions/waivers.
Apple Public Source License (APSL)
debian-legal http://lists.debian.org/debian-legal/2004/06/msg00573.html (v2.0)
GNU Free Documentation License (GFDL)
debian-legal See http://people.debian.org/~srivasta/Position_Statement.xhtml
Status (Vote) http://www.debian.org/vote/2006/vote_001
See also Wikipedia's GNU_Free_Documentation_License
See also on going effort to detect this license under qa
Data licensed under the FDL with no invariant sections are considered DFSG-free as of GR 2006-001: http://www.debian.org/vote/2006/vote_001#outcome
Open Publication License (OPL) v1.0
License Text http://www.opencontent.org/openpub/
Discusion on debian-legal http://lists.debian.org/debian-legal/2004/debian-legal-200403/msg00226.html
Open Software License (OSL) v1.1
License Text http://www.opensource.org/licenses/osl.php
Discussion on debian-legal
Creative Commons Attribution License (CC-by), v1.0
License Text http://creativecommons.org/licenses/by/1.0/legalcode
Discussion on debian-legal http://lists.debian.org/debian-legal/2004/debian-legal-200404/msg00031.html
It is believed that 2.0 still has problems (http://evan.prodromou.name/ccsummary/ccsummary.html), but it is under discussion between debian-legal and cc-licenses.
Creative Commons Attribution-Non Commercial-Share Alike (CC-by-nc-sa)
Creative Commons Attribution-Share Alike Generic (CC-BY-SA), v1.0
Discussion on debian-legal See above for CC-BY v1.0.
Creative Commons Sampling Plus (CC-sampling+), v1.0
Discussion on debian-legal http://lists.debian.org/debian-legal/2007/05/msg00092.html
JSON evil license
License Text http://www.json.org/license.html
Infamous for the clause The Software shall be used for Good, not Evil.
On going effort to remove on qa
License for OpenPBS and Torque
Swiss Ephemeris Public License
This license is non free:
Upstream relicense under GPL
RealNetworks Public Source License (RPSL)
- Note that SPIN licensed software can not be distributed in non-free section
Common Public Attribution License
License Text http://opensource.org/licenses/cpal_1.0
Issue: Badgeware license
Examples: Openproj, OpenEMM
Public Domain could be a special case worth additional notes here.
A FAQ follows, extracted from:
"License": public-domain in the debian-mentors mailing list https://lists.debian.org/debian-mentors/2017/09/msg00171.html
Q: Since software "placed in the public domain" has no license isn't it not under a free software license, and therefore not acceptable as free software according to the DFSG? A:
A:Software placed in the public domain has all the freedoms required by the DFSG, and is free software.
Q: Public Domain in debian/copyright files? Example: Copyright: John Doe License: public-domain These two statements seems to contradict each other: public domain means exactly the _absence_ of copyright. A:
Copyright: John Doe
These two statements seems to contradict each other: public domain means exactly the _absence_ of copyright.
A:The Copyright: field in this case is usually indicating who holds any residual copyright or author's rights in a jurisdiction which does not completely support public domain (PD). It also indicates who the individual was who dedicated the work to the PD.
Q: Specifically, public domain is _not_ open source A:
A:Public Domain works are not necessarily open source in all jurisdictions, but they can satisfy the DFSG in many.
Q: Since Debian is usually quite careful when it comes to legal issues, I'm wondering what the official view point is here? A:
A:The official viewpoint is that the software must meet the requirements of the DFSG. Generally, a CC0-style PD dedication is viewed as sufficient for all jurisdictions, and can satisfy the DFSG if source is available.
Q: Jurisdictions for Public Domain? A:
A:We are unaware of a case where a jurisdiction has upheld a copyright claim to a work which has been dedicated to the public domain everywhere. This is a potential theoretical source of problems, but there's enough actual problems with copyright and licensing for us to concentrate our limited time on them instead.
Q: Should there be a lintian error if the "license" is Public Domain and a copyright holder is specified? A:
Q: Should Public Domain perhaps be prohibited in general? A:
A note on terminology
Debian classifies software which has been packaged for it, in order to decide which section it should go in, if any. It is possible to use a DFSG-compatible license in a way that doesn't follow the DFSG, as pine shows. Anyone writing about a "free" or "non-free" license is probably abbreviating. That's not always a bad thing, but don't get confused by it.
Additionally, debian-legal contributors sometimes comment on licenses the list is asked about, because of ?ITPs or consultations. Those comments often include remarks about a term being "non-free" as a shorthand. Shorthands are good, but try not to get confused by it. debian-legal is not (and should not be turned into) FSF v2 or OSI v2.
If the license isn't on this list
If the license you're concerned about isn't on this short informal list, it may well have been discussed on debian-legal anyway. You can go to http://www.google.com/advanced_search; in the 'Domain' field, put in lists.debian.org. In the 'With all of the words' field, put in (at least) debian-legal. Then fill in the other fields as appropriate for searching for your license. Putting in a distinctive phrase from the license in the 'With the exact phrase' field is a good bet.