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 licences, 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 licences listed here are linked to the http://opensource.org/ site. If you find a link to the licence on the original site, feel free to change it.

The sections on this page are:

The Big DFSG-compatible Licenses

We consider a "big licence" to be well known and either widely used, or used by very important projects.

The GNU General Public Licence (GPL)

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

This is the most popular free software license. 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 Licence (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 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.php

Perl is licensed under the Artistic License.

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 :-)

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.

Minor DFSG-Capable Licenses

The formal criterion I'm using for "Minor" is that it is used only by a single software copyright holder. The informal criterion is that I'd never heard of it and never heard of the project it licenses. If you want to use a different criterion, go ahead and modify this ?WikiWiki page.

Petris License

http://lists.debian.org/debian-legal/2004/debian-legal-200402/msg00270.html


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.

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).

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.


Licenses that are DFSG-incompatible

These licences seem impossible to use in a way that follows DFSG without significant exceptions/waivers.

GNU Free Documentation License (GFDL)

Open Publication License (OPL) v1.0

Open Software License (OSL) v1.1

Consequences

Because the OSL is not free, we do not include elfutils in Debian: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=221761

This, in turn, means that we do not include rpm 4.2 and later, since rpm depends upon elfutils. That's why sarge/main's version of rpm is at 4.0, and likely to stay there.

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

It is believed that 2.0 still has problems, but it is under discussion between debian-legal and cc-licenses.

License for OpenPBS and Torque

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

Swiss Ephemeris Public License

RealNetworks Public Source License (RPSL)

Mozilla Public License (MPL)


More Resources

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

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 licence in a way that doesn't follow the DFSG, as pine shows. Anyone writing about a "free" or "non-free" licence is probably abbreviating. That's not always a bad thing, but don't get confused by it.

Additionally, debian-legal contributors sometimes comment on licences 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.