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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 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)

http://www.gnu.org/copyleft/gpl.html

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)

http://www.gnu.org/copyleft/lesser.html

(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)

http://www.apache.org/LICENSE.txt

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.

http://www.apache.org/licenses/

Mozilla Public License (MPL)

http://www.mozilla.org/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

http://www.opensource.org/licenses/bsd-license.php

(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

http://www.opensource.org/licenses/artistic-license-1.0.php

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

http://www.opensource.org/licenses/mit-license.php:

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.

Consequences

pine is not part of Debian.

The Open Font License

http://scripts.sil.org/cms/scripts/page.php?item_id=OFL_web

The following restriction on distributions, which is part of OFL, has been widely accepted by open source projects when it is applied to fonts:

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

See the IBM Public License, immediately below.

IBM Public License, Version 1.0

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.


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

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.

X-Oz License

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)

Might not pass DissidentTest. Problems in the translation slow down approval to a halt.


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)

GNU Free Documentation License (GFDL)

Exception

Open Publication License (OPL) v1.0

Open Software License (OSL) v1.1

Creative Commons Attribution License (CC-by), v1.0

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-Share Alike Generic (CC-BY-SA), v1.0

Creative Commons Sampling Plus (CC-sampling+), v1.0

JSON evil license

License for OpenPBS and Torque

http://lists.debian.org/debian-legal/2004/debian-legal-200403/msg00222.html

Swiss Ephemeris Public License

This license is non free:

Upstream relicense under GPL

RealNetworks Public Source License (RPSL)

SPIN License

Common Public Attribution License

Issue: http://lwn.net/Articles/243841/ Badgeware license

Examples: Openproj, OpenEMM


More Resources

http://lists.debian.org/debian-legal/2004/debian-legal-200403/msg00222.html

Public Domain

Although not a license, but a disclaim of copyright, this should be described here (or somewhere on the wiki as well).

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.