Various Licenses and Comments about Them
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Various Licenses and Comments about Them
Table of Contents
Introduction
Software Licenses
GPL-Compatible Free Software Licenses
GPL-Incompatible Free Software Licenses
Nonfree Software Licenses
Licenses For Documentation
Free Documentation Licenses
Nonfree Documentation Licenses
Licenses for Other Works
Licenses for Works of Practical Use
besides Software and Documentation
Licenses for Fonts
Licenses for Works stating a Viewpoint
(e.g., Opinion or Testimony)
Licenses for Designs for Physical Objects
This page is maintained by the Free Software
Foundation's Licensing and Compliance Lab. You can support our efforts by
making a donation
to the FSF.
You can use our publications to understand how GNU licenses work or help
you advocate for free software, but they are not legal advice. The FSF
cannot give legal advice. Legal advice is personalized advice from a
lawyer who has agreed to work for you. Our answers address general
questions and may not apply in your specific legal situation.
Have a
question not answered here? Check out some of our other
licensing resources
or contact the
Compliance Lab at
licensing@fsf.org
Introduction
We classify a license according to certain key criteria:
Whether it qualifies as a
free software
license.
Whether it is a
copyleft
license.
Whether it is
compatible with
the GNU GPL
. Unless otherwise specified, compatible licenses are
compatible with both GPLv2 and GPLv3.
Whether it causes any particular practical problems.
We try to list the most commonly encountered free software license on
this page, but cannot list them all; we'll try our best to answer
questions about free software licenses whether or not they are listed
here. The licenses are more or less in alphabetical order within each
section.
If you believe you have found a violation of one of our licenses,
please refer to our
license
violation page
If you've started a new project and you're not sure what license to
use,
“How to
choose a license for your own work”
details our
recommendations in an easy-to-follow guide.
If you have questions about free software licenses, you can email
us
at
Because our resources are limited, we do not answer questions that are
meant to assist proprietary software development or distribution, and
you'll likely get an answer faster if you ask a specific question that
isn't already covered here or in
our
FAQ
. We
welcome knowledgeable
volunteers
who want to help answer licensing questions.
If you are contemplating writing a new license, please also contact
us at
. The
proliferation of different free software licenses is a significant
problem in the free software community today, both for users and
developers. We will do our best to help you find an existing free
software license that meets your needs.
If you are wondering what license a particular software package is
using, please visit the
Free
Software Directory
, which catalogs thousands of free software
packages and their licensing information.
Software Licenses
GPL-Compatible Free Software Licenses
#GPLCompatibleLicenses
The following licenses qualify as
free software
licenses, and
are
compatible
with the
GNU GPL
GNU General Public License (GPL) version 3
#GNUGPL
#GNUGPLv3
This is the latest version of the GNU GPL: a free software license, and
a copyleft license. We recommend it for most software packages.
Please note that GPLv3 is not compatible with GPLv2 by itself.
However, most software released under GPLv2 allows you to use the
terms of later versions of the GPL as well. When this is the case,
you can use the code under GPLv3 to make the desired combination. To
learn more about compatibility between GNU licenses,
please
see our
FAQ
GNU General Public License (GPL) version 2
#GPLv2
This is the previous version of the GNU GPL: a free software license, and
a copyleft license. We recommend
the latest version
for most software.
Please note that GPLv2 is, by itself, not compatible with GPLv3.
However, most software released under GPLv2 allows you to use the
terms of later versions of the GPL as well. When this is the case,
you can use the code under GPLv3 to make the desired combination. To
learn more about compatibility between GNU licenses,
please
see our
FAQ
GNU Lesser General Public License (LGPL) version 3
#LGPL
#LGPLv3
This is the latest version of the LGPL: a free software license, but not
a strong copyleft license, because it permits linking with nonfree
modules. It is compatible with GPLv3. We recommend it for
special circumstances
only
Please note that LGPLv3 is not compatible with GPLv2 by itself.
However, most software released under GPLv2 allows you to use the
terms of later versions of the GPL as well. When this is the case,
you can use the code under GPLv3 to make the desired combination. To
learn more about compatibility between GNU licenses,
please
see our
FAQ
GNU Lesser General Public License (LGPL) version 2.1
#LGPLv2.1
This is the previous version of the LGPL: a free software license,
but not a strong copyleft license, because it permits linking with
nonfree modules. It is compatible with GPLv2 and GPLv3. We
generally recommend
the latest version of the
LGPL
for special
circumstances only
. To learn more about how LGPLv2.1 is
compatible with other GNU licenses,
please
see our
FAQ
GNU Affero General Public License (AGPL) version 3
#AGPL
#AGPLv3.0
This is a free software, copyleft license. Its terms effectively
consist of the terms of GPLv3, with an additional paragraph in section 13
to allow users who interact with the licensed software over a network to
receive the source for that program. We recommend that developers consider
using the GNU AGPL for any software which will commonly be run over a
network.
Please note that the GNU AGPL is not compatible with GPLv2. It is
also technically not compatible with GPLv3 in a strict sense: you
cannot take code released under the GNU AGPL and convey or modify it
however you like under the terms of GPLv3, or vice versa. However,
you are allowed to combine separate modules or source files released
under both of those licenses in a single project, which will provide
many programmers with all the permission they need to make the
programs they want. See section 13 of both licenses for
details.
GNU All-Permissive License
#GNUAllPermissive
This is a lax, permissive free software license, compatible with
the GNU GPL, which we recommend GNU packages use for README and other
small supporting files. All developers can feel free to use it in
similar situations.
Older versions of this license did not have the second sentence with
the express warranty disclaimer. This same analysis applies to both
versions.
Apache License, Version 2.0
#apache2
This is a free software license, compatible with version 3 of the
GNU GPL.
Please note that this license is not compatible with GPL version 2,
because it has some requirements that are not in that GPL version.
These include certain patent termination and indemnification
provisions. The patent termination provision is a good thing, which
is why we recommend the Apache 2.0 license for substantial programs
over other lax permissive licenses.
Artistic License 2.0
#ArtisticLicense2
This license is a free software license, compatible with the GPL
thanks to the relicensing option in section 4(c)(ii).
Clarified Artistic License
#ClarifiedArtistic
This license is a free software license, compatible with the GPL. It
is the minimal set of changes needed to correct the vagueness of the
Artistic License 1.0
Berkeley Database License
(a.k.a. the Sleepycat Software Product License)
#BerkeleyDB
This is a free software license, compatible with the GNU GPL.
Boost Software License
#boost
This is a lax, permissive non-copyleft free software license,
compatible with the GNU GPL.
Modified BSD license
#ModifiedBSD
This is the original BSD license, modified by removal of the
advertising clause. It is a lax, permissive non-copyleft free
software license, compatible with the GNU GPL.
This license is sometimes referred to as the 3-clause BSD license.
The modified BSD license is not bad, as lax permissive licenses go,
though the Apache 2.0 license is preferable. However, it is risky to
recommend use of “the BSD license”, even for special cases
such as small programs, because confusion could easily occur and lead
to use of the flawed
original
BSD
license
. To avoid this risk, you can suggest the X11 license
instead. The X11 license and the modified BSD license are
more or less equivalent.
However, the Apache 2.0 license is better for substantial programs,
since it prevents patent treachery.
CeCILL version 2
#CeCILL
The CeCILL is a free software license, explicitly compatible with the
GNU GPL.
The text of the CeCILL uses a couple of biased terms that ought to be
avoided:
“intellectual property”
and
“protection”
; this decision
was unfortunate, because reading the license tends to spread the
presuppositions of those terms. However, this does not cause any
particular problem for the programs released under the CeCILL.
Section 9.4 of the CeCILL commits the program's developers to certain
forms of cooperation with the users, if someone attacks the program
with a patent. You might look at that as a problem for the developer;
however, if you are sure you would want to cooperate with the users in
those ways anyway, then it isn't a problem for you.
The Clear BSD License
#clearbsd
This is a free software license, compatible with both GPLv2 and
GPLv3. It is based on the
modified BSD
license
, and adds a term expressly stating it does not grant you
any patent licenses. Because of this, we encourage you to be careful
about using software under this license; you should first consider
whether the licensor might want to sue you for patent infringement.
If the developer is refusing users patent licenses to set up a trap
for you, it would be wise to avoid the program.
Cryptix General License
#CryptixGeneralLicense
This is a lax, permissive non-copyleft free software license,
compatible with the GNU GPL. It is nearly identical to the
FreeBSD (also
called “2-clause BSD”) license
eCos license version 2.0
#eCos2.0
The eCos license version 2.0 is a GPL-compatible free software
license. It consists of the GPL, plus an exception allowing linking to
software not under the GPL. This license has the same
disadvantages
as the LGPL.
Educational Community License 2.0
#ECL2.0
This is a free software license, and it is compatible with
GPLv3. It is based on the
Apache License
2.0
; the scope of the patent license has changed so that when
an organization's employee works on a project, the organization
does not have to license all of its patents to recipients. This
patent license and the indemnification clause in section 9 make
this license incompatible with GPLv2.
Eiffel Forum License, version 2
#Eiffel
This is a free software license, compatible with the GNU GPL.
Previous
releases
of the Eiffel license are not compatible with the
GPL.
EU DataGrid Software License
#EUDataGrid
This is a lax, permissive non-copyleft free software license,
compatible with the GNU GPL.
Expat License
#Expat
This is a lax, permissive non-copyleft free software license,
compatible with the GNU GPL.
Some people call this license “the MIT License,” but
that term is misleading, since MIT has used many licenses for
software. It is also ambiguous, since the same people also call
the
X11 license
“the MIT License,”
failing to distinguish them. We recommend not using the term “MIT
License.”
The difference between the X11 license and the Expat license is
that the X11 license contains an extra paragraph about using the X
Consortium's name. It is not a big deal, but it is a real
difference.
For substantial programs it is better to use the Apache 2.0 license
since it blocks patent treachery.
Expat No Attribution License
#Expat0
Some people call this license “the MIT No Attribution License,”
but that term is misleading, since MIT has used many licenses for software and
all of them contained requirements to preserve copyright notices and license
notice. As the license is clearly based on the Expat License, we recommend to
call it the No-attribution Expat License (but please note that Expat has never
used this license).
The only difference between this license and the Expat License is that it
doesn't contain clauses that require preserving copyright notices and the
license notice.
Our comments about the
Zero-clause BSD license
apply
to this license.
FreeBSD license
#FreeBSD
This is the original BSD license with the advertising clause and
another clause removed. (It is also sometimes called the
“2-clause BSD license”.) It is a lax, permissive
non-copyleft free software license, compatible with the GNU GPL.
Our comments about the
Modified BSD license
apply to this license too.
Freetype Project License
#freetype
This is a free software license, and compatible with GPLv3. It has
some attribution requirements which make it incompatible with
GPLv2.
Historical Permission Notice and Disclaimer
#HPND
This is a lax, permissive, and weak free software license that is
compatible with the GPL. It is similar to the license of
Python 1.6a2 and earlier versions
License of the iMatix Standard Function Library
#iMatix
This is a free software license and is GPL compatible.
License of imlib2
#imlib
This is a free software license, and GPL-compatible. The author has
explained to us that the GPL's options for providing source all mean the
source has been “made available publicly” in their
words.
Independent JPEG Group License
#ijg
This is a free software license, and compatible with the GNU GPL.
The authors have assured us that developers who document changes as
required by the GPL will also comply with the similar requirement in
this license.
Informal license
#informal
An “informal license” means a statement such as
“do whatever you like with this” or “you can
redistribute this code and change it.”
In the United States, these licenses are supposed to be interpreted
based on what the author seems to intend. So they probably mean what
they appear to mean. That would make them non-copyleft free software
licenses and compatible with the GNU GPL. However, an unlucky choice
of wording could give it a different meaning.
However, many other countries have a more rigid approach to
copyright licenses. There is no telling what courts in those
countries might decide an informal statement means. Courts might
even decide that it is not a license at all.
If you want your code to be free, don't invite gratuitous trouble
for your users. Please choose and apply an established free software
license. We offer
recommendations
that we suggest you follow.
Intel Open Source License
#intel
This is a free software license, compatible with the GNU GPL.
ISC License
#ISC
This license is sometimes also known as the OpenBSD License. It is a free
software license, and compatible with the GNU GPL.
This license had an unfortunate wording choice: it provided recipients with
“Permission to use, copy, modify, and distribute this
software…” This was the same language from the license of Pine that
the University of Washington later claimed prohibited people from distributing
modified versions of the software.
ISC has told us they do not share the University of Washington's
interpretation, and we have every reason to believe them. ISC also updated the
license to read “Permission to use, copy, modify,
and/or
distribute this software…” While the inclusion of
“and/or” doesn't completely solve the issue, there's no reason to
avoid software released under this license. However, to help make sure this
language cannot cause any trouble in the future, we encourage developers to
choose a different license for their own works. The
FreeBSD
License
is similarly permissive and brief. However, if you want a lax, weak
license, we recommend using the Apache 2.0 license.
Mozilla Public
License (MPL) version 2.0
#MPL-2.0
This is a free software license. Section 3.3 provides indirect
compatibility between this license and the GNU GPL version 2.0, the
GNU LGPL version 2.1, the GNU AGPL version 3, and all later versions
of those licenses. When you receive work under MPL 2.0,
you may make a “Larger Work” that combines that work with
work under those GNU licenses. When you do, section 3.3 gives
you permission to distribute the MPL-covered work under the terms of
the same GNU licenses, with one condition: you must make sure that the
files that were originally under the MPL are still available under the
MPL's terms as well. In other words, when you make a combination this
way, the files that were originally under the MPL will be dual
licensed under the MPL and the GNU license(s). The end result is that
the Larger Work, as a whole, will be covered under the GNU license(s).
People who receive that combination from you will have the option to
use any files that were originally covered by the MPL under that
license's terms, or distribute the Larger Work in whole or in part
under the GNU licenses' terms with no further restrictions.
It's important to understand that the condition to distribute files
under the MPL's terms only applies to the party that first creates and
distributes the Larger Work. If it applied to their recipients as well, it
would be a further restriction and incompatible with the GPL and AGPL.
That said, when you make contributions to an existing project, we usually
recommend that you
keep your changes under the same license
even when you're not required to do so. If you receive a work under a GNU
license where some files are also under the MPL, you should only remove the
MPL from those files when there's a strong reason to justify it.
Check the license notices on the MPL-covered software before you make
a Larger Work this way. Parties who release original work under
MPL 2.0 may choose to opt out of this compatibility by
including a sentence in the license notices that says that the work is
“Incompatible With Secondary Licenses.” Any software that
includes this notice is
not
compatible with the GPL
or AGPL.
Software under previous versions of the MPL can be upgraded to version
2.0, but any software that isn't already available under one of the
listed GNU licenses
must
be marked as Incompatible With Secondary
Licenses. This means that software that's only available under
previous versions of the MPL is still incompatible with the GPL and AGPL.
NCSA/University of Illinois Open Source License
#NCSA
This license is based on the terms of the
Expat
and
modified BSD
licenses. It is a lax,
permissive non-copyleft free software license, compatible with the GNU
GPL.
License of Netscape JavaScript
#NetscapeJavaScript
This is the disjunction of the
Netscape Public
License
and the
GNU GPL
. Because
of that, it is a free software license, compatible with the GNU GPL, but
not a strong copyleft.
OpenLDAP License, Version 2.7
#newOpenLDAP
This is a permissive non-copyleft free software license that is
compatible with the GNU GPL.
License of Perl 5 and below
#PerlLicense
This license is the disjunction of the
Artistic License 1.0
and the
GNU GPL
—in other words,
you can choose either of those two licenses. It qualifies as a free
software license, but it may not be a real copyleft. It is compatible
with the
GNU GPL
because the GNU GPL is one of the alternatives.
We recommend you use this license for any Perl 4 or Perl 5 package
you write, to promote coherence and uniformity in Perl programming.
Outside of Perl, we urge you not to use this license; it is better to
use just the GNU GPL.
Public Domain
#PublicDomain
Being in the public domain is not a license; rather, it means the
material is not copyrighted and no license is needed. Practically
speaking, though, if a work is in the public domain, it might as well
have an all-permissive non-copyleft free software license. Public
domain material is compatible with the GNU GPL.
If you want to release your work to the public domain, we encourage
you to use formal tools to do so. Our solution is to ask people who
make small contributions to GNU to sign a disclaimer form. If you're
working on a project that doesn't have formal contribution policies,
contact the project to discuss how best to contribute within the
project's licensing model.
License of Python 2.0.1, 2.1.1, and newer versions
#Python
This is a free software license and is compatible with the GNU GPL.
Please note, however, that intermediate versions of Python (1.6b1,
through 2.0 and 2.1) are under a different license (
see below
).
License of Python 1.6a2 and earlier versions
#Python1.6a2
This is a free software license and is compatible with the GNU GPL.
Please note, however, that newer versions of Python are under other
licenses (see above and below).
License of Ruby
#Ruby
This is a free software license, compatible with the GPL via an
explicit dual-licensing clause.
SGI Free Software License B, version 2.0
#SGIFreeB
The SGI Free Software License B version 2.0 is a free software
license. It is essentially identical to the
X11
License
, with an optional alternative way of providing license
notices.
Previous versions of the SGI Free Software License B were not free
software licenses, despite their name. However, they all included
clauses that allow you to upgrade to new versions of the license, if you
choose to do so. As a result, if a piece of software was released under
any version of the SGI Free License B, you can use it under the terms of
this free version.
Standard ML of New Jersey Copyright License
#StandardMLofNJ
This is a lax, permissive non-copyleft free software license,
compatible with the GNU GPL.
Unicode, Inc. License Agreement for Data Files and Software
#Unicode
This is a license that Unicode, Inc. has applied to the Unicode
Character Database—various data files that developers can use to
help implement the Unicode standard in their own programs. It is a
lax permissive license, compatible with all versions of the GPL.
If you want to use files covered by this License Agreement in your
own software, that shouldn't be any problem, but we recommend that
you also include a full copy of its text. Some of the files contain
alternative license terms which are nonfree, or no licensing
information at all, so including a copy of the License Agreement
will help avoid confusion when others want to distribute your
software. Of course, you'll also need to follow the conditions in
this License Agreement for distributing the files, but those are
very straightforward.
Please take care to ensure that the files you are using are covered
by this License Agreement. Other files published by Unicode,
Inc. are covered by the Unicode Terms of Use, a different, nonfree
license that appears on the same page but covers different files. A
short explanation at the top of this License Agreement details
which files it covers.
Please do not use this License Agreement for your own software. If
you want to use a lax permissive license for your project, please use
the
Expat license
for a small program and the
Apache 2.0 license for a substantial program. These are far more
common, and widely recognized in the free software community.
Unicode License v3
#Unicodev3
This is version 3 of the license that Unicode, Inc. has applied to
various data files and software that developers can use to help
implement the Unicode standard in their own programs. It is a lax,
permissive, free software license, compatible with all versions of the
GNU GPL.
It differs from earlier versions as it does not include specific
references to Unicode. This makes it possible to use the Unicode v3
license as a template to release other data or software under
it.
Please do not use this License Agreement for your own software. If
you want to use a lax permissive license for your project, please use
Expat license
for a small program and the Apache
2.0 license for a substantial program. These are far more common, and
widely recognized in the free software community. However, it is
usually better for the advance of free software
to use
a copyleft license
Additionally, if you want to use the Unicode Character Database
files, please take care to ensure that the files you are using are
covered by this License Agreement only. The Unicode Terms of Use, a
different, nonfree license does not provide clear guidelines whether a
particular file is subject to any additional restrictions. It includes
clauses such as “Each version of the Unicode Standard has further
specifications of rights and restrictions of use.”
Universal Permissive License (UPL)
#UPL
This is a lax, permissive non-copyleft free software license, compatible
with the GNU GPL. The license does provide the ability to license
patents along with the software work, however, we still recommend the
Apache 2.0 license for avoiding patent treachery when choosing to put
your work under a lax license.
The Unlicense
#Unlicense
The Unlicense is a public domain dedication. A work released
under the Unlicense is dedicated to the public domain to the fullest
extent permitted by law, and also comes with an additional lax
license that helps cover any cases where the dedication is inadequate.
Both public domain works and the lax license provided by the
Unlicense are compatible with the GNU GPL.
License of Vim, Version 6.1 or later
#Vim
This is a free software license, partially copyleft but not
really. It is compatible with the GPL, by an explicit conversion
clause.
W3C Software Notice and License
#W3C
This is a free software license and is GPL compatible.
License of WebM
#WebM
Google's WebM implementation is covered by the
Modified BSD License
. Google also provides a
separate patent license (confusingly called an “Additional IP
Rights Grant”) for patents that Google owns or controls that are
necessarily infringed by their implementation of WebM. GPL-covered
software can be distributed in compliance with this license's terms: it
allows distributors to exercise all of the rights granted by the GPL,
while fulfilling all its conditions. Thus, all of WebM's license is
free and GPL-compatible.
WTFPL, Version 2
#WTFPL
This is a lax permissive non-copyleft free software license,
compatible with the GNU GPL.
We do not recommend this license. If you want a lax permissive
license for a small program, we recommend
the
X11 license
. A larger program usually
ought to be copyleft; but if you are set on using a lax permissive
license for one, we recommend the Apache 2.0 license since it protects
users from patent treachery.
WxWidgets Library License
#Wx
The WxWidgets license is a GPL-compatible free software license. It
consists of the
GNU
Lesser GPL 2.0
or any later version, plus an additional permission
allowing binary distributions that use the library to be licensed
under terms of the distributor's choice (including proprietary). It
is a weak copyleft, even weaker than the LGPL, so we recommend
it
only in special
circumstances
WxWindows Library License
#Wxwind
An older name for the
WxWidgets Library license
X11 License
#X11License
This is a lax permissive non-copyleft free software license,
compatible with the GNU GPL. Older versions of XFree86 used the same
license, and some of the current variants of XFree86 also do. Later
versions of XFree86 are distributed under the
XFree86 1.1 license
Some people call this license “the MIT License,” but
that term is misleading, since MIT has used many licenses for
software. It is also ambiguous, since the same people also call
the
Expat license
“the MIT License,”
failing to distinguish them. We recommend not using the term “MIT
License.”
The difference between the X11 license and the Expat license is
that the X11 license contains an extra paragraph about using the X
Consortium's name. It is not a big deal, but it is a real
difference.
This is a fine license for a small program. A larger program
usually ought to be copyleft; but if you are set on a lax permissive
license for one, we recommend the Apache 2.0 license since it protects
users from patent treachery.
XFree86 1.1 License
#XFree861.1License
This is a lax, permissive non-copyleft free software license,
compatible with version 3 of the GPL.
Please note that this license is incompatible with version 2 of the GPL,
because of its requirements that apply to all documentation in the
distribution that contain acknowledgements.
There are currently several variants of XFree86, and only some of
them use this license. Some continue to use the
X11 license
Zero-clause BSD license
#Zero-BSD
This license is also known as 0BSD License. Contrary to its name, it is not
based on any of the BSD licenses, but on the
ISC License
with the only difference being that it doesn't contain clauses that require
preservation of copyright notices and the license notice. Accordingly, there is
also no placeholder for copyright notice in the template of this license
circulating in the internet.
The Zero-clause BSD License can operate as a free software license compatible
with the GNU GPL, but if the copyright notice or license notice is removed from
the program, it is not possible to safely rely on the license and users might
even face liability. If you want the shortest unproblematical license, we think
it is wiser to use the
FreeBSD License
, as it is
similarly permissive and brief.
However, if you are looking for the best among lax, weak licenses, we
recommend using the Apache 2.0 license among those.
The lack of requirement to preserve copyright notices and the license notice
does not necessarily mean it is safe to remove them. In some jurisdictions,
removing copyright-related information may constitute copyright infringement.
Additionally, if you remove copyright notices, users who receive software from
you are not able to identify who is giving them permission to use the software.
If you also remove the license notice, users end up confused about whether they
received a free or a nonfree program. We recommend that developers choose a
license that clearly requires preserving notices for their own works because of
the confusion and antisocial effect that is the result of the 0BSD License.
While there is no reason to avoid software already released under this
license provided that the copyright notices and license notice are not removed,
we recommend that when using such software, developers do not remove any
copyright notices attached to it and the license notice itself. This helps to
avoid the confusion and antisocial effect described above.
License of ZLib
#ZLib
This is a free software license, and compatible with the GPL.
Zope Public License, versions 2.0 and 2.1
#Zope2.0
This is a lax, permissive non-copyleft free software license
which is compatible with the GNU GPL.
GPL-Incompatible Free Software Licenses
#GPLIncompatibleLicenses
The following licenses
are
free software
licenses, but
are
not
compatible
with the
GNU GPL
Affero General Public License version 1
#AGPLv1.0
The Affero General Public License is a free software license,
copyleft, and incompatible with the GNU GPL. It consists of the GNU GPL
version 2, with one additional section that Affero added with FSF
approval. The new section, 2(d), covers the distribution of application
programs through web services or computer networks.
This license has been succeeded by the
GNU Affero
General Public License version 3
; please use that instead.
Academic Free License, all versions through 3.0
#AcademicFreeLicense
The Academic Free License is a free software license, not copyleft, and
incompatible with the GNU GPL. Recent versions contain contract clauses
similar to the
Open Software License
, and should be
avoided for the same reasons.
Apache License, Version 1.1
#apache1.1
This is a permissive non-copyleft free software license. It has a few
requirements that render it incompatible with the GNU GPL, such as strong
prohibitions on the use of Apache-related names.
Apache License, Version 1.0
#apache1
This is a lax, permissive non-copyleft free software license with an
advertising clause. This creates
practical problems
like
those of the original BSD license, including incompatibility with the GNU
GPL.
Apple Public Source License (APSL), version 2
#apsl2
This is a free software license, incompatible with the GNU GPL. We
recommend that you not use this license for new software that you write,
but it is ok to use and improve the software released under this
license.
More
explanation.
BitTorrent Open Source License
#bittorrent
This is a free software license, but incompatible with the GPL,
for the same reasons as the
Jabber Open Source
License
Original BSD license
#OriginalBSD
This license is also sometimes called the
“4-clause BSD license”.
This is a lax, permissive non-copyleft free software license with
a serious flaw: the “obnoxious BSD advertising clause”. The
flaw is not fatal; that is, it does not render the software nonfree.
But it does cause
practical problems
including incompatibility with the GNU GPL.
We urge you not to use the original BSD license for software you
write. If you want to use a lax, permissive non-copyleft free
software license, it is much better to use the
modified BSD license
, the X11 license
or the Expat license. Even better, for a substantial program,
use the Apache 2.0 license since it takes action against patent treachery.
However, there is no reason not to use programs that have been released
under the original BSD license.
CeCILL-B version 1
#CeCILL-B
The CeCILL-B is a free software license. It is incompatible with the
GPL because it has requirements that are not present in the GPL. The
credit requirements in section 5.3.4 exceed those of the GPL. It also
has a strange requirement that you use your “best efforts”
to get third parties to agree “to comply with the obligations set
forth in this Article.”
Please do not release software under this license.
CeCILL-C version 1
#CeCILL-C
The CeCILL-C is a free software license with a weak copyleft
somewhat like the
GNU Lesser General Public
License
. It is incompatible with the GNU GPL because it does not
contain the explicit GPL-compatibility clause of
the
basic CeCILL
Please do not release software under this license.
Common Development and Distribution License (CDDL), version 1.0
#CDDL
This is a free software license. It has a weak per-file copyleft
(like version 1 of the Mozilla Public License) which makes it
incompatible with the
GNU GPL
. This
means a module covered by the GPL and a module covered by the CDDL
cannot legally be linked together. We urge you not to use the CDDL
for this reason.
For an illustrative example of why you should not combine
CDDL-licensed works with the GPL-licensed works, see the FSF's
statement,
Interpreting, enforcing and changing the GNU GPL, as applied to
combining Linux and ZFS
Also unfortunate in the CDDL is its use of the term “
intellectual property
”.
Common Public Attribution License 1.0 (CPAL)
#CPAL
This is a free software license. It is based on the
Mozilla Public License
version 1, and is incompatible with the GPL
for the same reasons: it has several requirements for modified versions
that do not exist in the GPL. It also requires you to publish the
source of the program if you allow others to use it.
Common Public License Version 1.0
#CommonPublicLicense10
This is a free software license. Unfortunately, its weak copyleft
and choice of law clause make it incompatible with the GNU GPL.
Condor Public License
#Condor
Recent versions of Condor (from 6.9.5 on) are released under the
Apache License 2.0
. Only older versions of Condor
use this license.
The Condor Public License is a free software license. It has a
couple of requirements that make it incompatible with the GNU GPL,
including strong restrictions on the use of Condor-related names, and
requires redistributors to “represent and warrant” that
they will comply with United States export laws. (If it made
compliance an actual condition of the license, it would not be a free
software license.)
Eclipse Public License Version 1.0
#EPL
The Eclipse Public License is similar to the
Common Public License
, and our
comments on the CPL apply equally to the EPL. The only change is that
the EPL removes the broader patent retaliation language regarding patent
infringement suits specifically against Contributors to the EPL'd
program.
Eclipse Public License Version 2.0
#EPL2
In terms of GPL compatibility, the Eclipse Public License version
2.0 is essentially equivalent to version 1.0. The only change is that
it explicitly offers the option of designating the GNU GPL version 2
or later as a “secondary license” for a certain piece of
code.
If an initial contributor releases a specific piece of code and
designates GNU GPL version 2 or later as a secondary license, that
provides explicit compatibility with those GPL versions for that
code. (Doing so is roughly equivalent, for users, to releasing that
piece of code under a dual license, EPL | GPL.) However, the EPL2
without this designation remains incompatible with the GPL.
European Union Public License (EUPL) version 1.1
#EUPL-1.1
This is a free software license. By itself, it has a copyleft
comparable to the GPL's, and incompatible with it. However, it gives
recipients ways to relicense the work under the terms of other
selected licenses, and some of those—the
Eclipse
Public License
and the
Common
Public License
in particular—only provide a weaker copyleft.
Thus, developers can't rely on this license to provide a strong
copyleft.
The EUPL allows relicensing to GPLv2, because that is listed as one
of the alternative licenses that users may convert to. It also,
indirectly, allows relicensing to GPL version 3, because there is a
way to relicense to the CeCILL v2, and the CeCILL v2 gives a way to
relicense to any version of the GNU GPL.
To do this two-step relicensing, you need to first write a piece of
code which you can license under the CeCILL v2, or find a
suitable module already available that way, and add it to the
program. Adding that code to the EUPL-covered program provides
grounds to relicense it to the CeCILL v2. Then you need to write a
piece of code which you can license under the GPLv3-or-later, or find a
suitable module already available that way, and add it to the program.
Adding that code to the CeCILL-covered program provides grounds to
relicense it to GPLv3-or-later.
European Union Public License (EUPL) version 1.2
#EUPL-1.2
This is a free software license. By itself, it has a copyleft
comparable to the GPL's, and incompatible with it. However, it gives
recipients ways to relicense the work under the terms of other selected
licenses, and some of those—the Eclipse Public License in
particular—only provide a weaker copyleft. Thus, developers can't
rely on this license to provide a strong copyleft.
The EUPL allows relicensing to GPLv2 only and GPLv3 only, because
those licenses are listed as two of the alternative licenses that users
may convert to. It also, indirectly, allows relicensing to GPL
version 3 or any later version, because there is a way to relicense
to the CeCILL v2, and the CeCILL v2 gives a way to relicense to any
version of the GNU GPL.
To do this two-step relicensing, you need to first write a piece of code
which you can license under the CeCILL v2, or find a suitable module
already available that way, and add it to the program. Adding that code
to the EUPL-covered program provides grounds to relicense it to the
CeCILL v2. Then you need to write a piece of code which you can license
under the GPLv3-or-later, or find a suitable module already available that way,
and add it to the program. Adding that code to the CeCILL-covered
program provides grounds to relicense it to GPLv3-or-later.
Fraunhofer FDK AAC license
#fdk
This is a free software license as far as it goes. It is
incompatible with any version of the GNU GPL.
It has a special danger in the form of a term expressly stating it
does not grant you any patent licenses, with an invitation to buy
some. Because of this, and because the license author is a known
patent aggressor, we encourage you to be careful about using or
redistributing software under this license: you should first consider
whether the licensor might aim to lure you into patent infringement.
If you conclude that the program is bait for a patent trap, it would
be wise to avoid the program.
It is possible that the pertinent patents have expired. Depending on
whether Fraunhofer still has active patents covering the work, the
software might be a trap now, or not. (Of course, any program is
potentially threatened by patents, and the only way to end that is to
change patent law to
make software safe from patents
.)
Gnuplot license
#gnuplot
This is a free software license, incompatible with the GNU GPL.
IBM Public License, Version 1.0
#IBMPL
This is a free software license. Unfortunately, it has a choice of law
clause which makes it incompatible with the GNU GPL.
Jabber Open Source License, Version 1.0
#josl
The license is a free software license, incompatible with the GPL.
It permits relicensing under a certain class of licenses, those which
include all the requirements of the Jabber license. The GPL is not a
member of that class, so the Jabber license does not permit relicensing
under the GPL. Therefore, it is not compatible.
LaTeX Project Public License 1.3a
#LPPL-1.3a
We have not written a full analysis of this license, but it is a free
software license, with less stringent requirements on distribution than
LPPL 1.2 (described next). It is still incompatible with the GPL
because some modified versions must include a copy of or pointer to an
unmodified version.
LaTeX Project Public License 1.2
#LPPL-1.2
This license is an incomplete statement of the distribution terms
for LaTeX. As far as it goes, it is a free software license, but
incompatible with the
GPL
because it has
many requirements that are not in the GPL.
This license contains complex and annoying restrictions on how to
publish a modified version, including one requirement that falls just
barely on the good side of the line of what is acceptable: that any
modified file must have a new name.
The reason this requirement is acceptable for LaTeX is that TeX has
a facility to allow you to map file names, to specify “use file
bar when file foo is requested”. With this facility, the
requirement is merely annoying; without the facility, the same
requirement would be a serious obstacle, and we would have to conclude
it makes the program nonfree.
This condition may cause trouble with some major modifications.
For example, if you wanted to port an LPPL-covered work to another
system that lacked a similar remapping facility, but still required
users to request this file by name, you would need to implement a
remapping facility too to keep this software free. That would be a
nuisance, but the fact that a license would make code nonfree if
transplanted into a very different context does not make it nonfree in
the original context.
The LPPL says that some files, in certain versions of LaTeX, may have
additional restrictions, which could render them nonfree. For this
reason, it may take some careful checking to produce a version of
LaTeX that is free software.
The LPPL makes the controversial claim that simply having files on a
machine where a few other people could log in and access them in
itself constitutes distribution. We believe courts would not uphold
this claim, but it is not good for people to start making the claim.
Please do not use this license for any other project.
Note: These comments are for version 1.2 (3 Sep 1999) of the LPPL.
Lucent Public License Version 1.02 (Plan 9 license)
#lucent102
This is a free software license, but it is incompatible with the GNU GPL
because of its choice of law clause. We recommend that you not use this
license for new software that you write, but it is ok to use and improve
Plan 9 under this license.
Microsoft Public License (Ms-PL)
#ms-pl
This is a free software license; it has a copyleft that is not
strong, but incompatible with the GNU GPL. We urge you not to use
the Ms-PL for this reason.
Microsoft Reciprocal License (Ms-RL)
#ms-rl
This is a free software license. It's based on the
Microsoft Public License
, and has an additional clause
to make the copyleft just a little bit stronger. It's also incompatible
with the GNU GPL, and we urge you not to use the Ms-RL for this
reason.
Mozilla Public License (MPL) version 1.1
#MPL
This is a free software license which is not a strong copyleft;
unlike the
X11 license
, it has some complex
restrictions that make it incompatible with
the
GNU GPL
. That is, a module
covered by the GPL and a module covered by the MPL cannot legally be
linked together. We urge you not to use the MPL 1.1 for this
reason.
However, MPL 1.1 has a provision (section 13) that allows a program
(or parts of it) to offer a choice of another license as well. If part
of a program allows the GNU GPL as an alternate choice, or any other
GPL-compatible license as an alternate choice, that part of the program
has a GPL-compatible license.
MPL version 2.0 has a number of improvements, including
GPL-compatibility by default.
See that entry
for details.
Netizen Open Source License (NOSL), Version 1.0
#NOSL
This is a free software license that is essentially the same as the
Mozilla Public License version 1.1. Like the MPL, the NOSL has some
complex restrictions that make it incompatible with the GNU GPL. That
is, a module covered by the GPL and a module covered by the NOSL cannot
legally be linked together. We urge you not to use the NOSL for this
reason.
Netscape Public License (NPL)
, versions 1.0 and 1.1
#NPL
This is a free software license, not a strong copyleft, and
incompatible with the GNU GPL. It consists of the Mozilla Public
License version 1.1 with an added clause that permits Netscape to use
your added code
even in their proprietary versions of the
program
. Of course, they do not give
you
permission to
use
their
code in the analogous
way.
We urge you not to use
the NPL.
Nokia Open Source License
#Nokia
This is similar to the Mozilla Public License version 1: a free
software license incompatible with the GNU GPL.
Old OpenLDAP License, Version 2.3
#oldOpenLDAP
This is a permissive non-copyleft free software license with a few
requirements (in sections 4 and 5) that render it incompatible with
the GNU GPL. Note that the latest version of OpenLDAP has
different license
that is compatible with
the GNU GPL.
We urge you not to use the older OpenLDAP license for software you
write. However, there is no reason to avoid running programs that have
been released under this license.
Open Software License, all versions through 3.0
#OSL
The Open Software License is a free software license. It is
incompatible with the GNU GPL in several ways.
Recent versions of the Open Software License have
a term which requires distributors to try to obtain explicit assent to
the license. This means that distributing OSL software on ordinary FTP
sites, sending patches to ordinary mailing lists, or storing the
software in an ordinary version control system, is arguably a violation
of the license and would subject you to possible termination of the
license. Thus, the Open Software License makes it very difficult to
develop software using the ordinary tools of free software development.
For this reason, and because it is incompatible with the GPL, we
recommend that no version of the OSL be used for any software.
We urge you not to use the Open Software License for software you
write. However, there is no reason to avoid running programs that
have been released under this license.
OpenSSL license
#OpenSSL
Recent versions of OpenSSL (from 3.0.0 on) are released under the
Apache License 2.0
. Only older versions of OpenSSL
use this license.
The license of OpenSSL is a conjunction of two licenses, one called
“OpenSSL License” and the other being the license of SSLeay. You must
follow both. The combination results in a copyleft free software
license that is incompatible with the GNU GPL. It also has an
advertising clause like the
original BSD
license
and the
Apache 1 license
We recommend using GNUTLS instead of OpenSSL in software you write.
However, there is no reason not to use OpenSSL and applications that
work with OpenSSL.
Phorum License, Version 2.0
#Phorum
This is a free software license but it is incompatible with the
GPL
. Section 5 makes
the license incompatible with the GPL.
PHP License, Version 3.01
#PHP-3.01
This license is used by most of PHP4. It is a non-copyleft free
software license. It is incompatible with the GNU GPL because it
includes strong restrictions on the use of “PHP” in the
name of derived products.
We recommend that you not use this license for anything except PHP
add-ons.
License of Python 1.6b1 through 2.0 and 2.1
#PythonOld
This is a free software license but is incompatible with the GNU GPL.
The primary incompatibility is that this Python license is governed by the
laws of the State of Virginia, in the USA, and the GPL does not permit
this.
Q Public License (QPL), Version 1.0
#QPL
This is a non-copyleft free software license which is incompatible with
the GNU GPL. It also causes major practical inconvenience, because modified
sources can only be distributed as patches.
We recommend that you avoid using the QPL for anything that you write,
and use QPL-covered software packages only when absolutely necessary.
However, this avoidance no longer applies to Qt itself, since Qt is
now also released under the GNU GPL.
Since the QPL is incompatible with the GNU GPL, you cannot take a
GPL-covered program and QPL-covered program and link them together, no
matter how.
However, if you have written a program that uses QPL-covered library
(called FOO), and you want to release your program under the GNU GPL,
you can easily do that. You can resolve the conflict
for your
program
by adding a notice like this to it:
As a special exception, you have permission to link this program
with the FOO library and distribute executables, as long as you
follow the requirements of the GNU GPL in regard to all of the
software in the executable aside from FOO.
You can do this, legally, if you are the copyright holder for the
program. Add it in the source files, after the notice that says
the program is covered by the GNU GPL.
RealNetworks Public Source License (RPSL), Version 1.0
#RPSL
The RPSL is a free software license that is GPL-incompatible for a
number of reasons: it requires that derivative works be licensed under the
terms of the RPSL, and mandates that any litigation take place in Seattle,
Washington.
Sun Industry Standards Source License 1.1
#SISSL
This is a free software license, not a strong copyleft, which is
incompatible with the GNU GPL because of details rather than any
major policy.
Sun Public License
#SPL
This is essentially the same as the Mozilla Public License version 1: a free
software license incompatible with the GNU GPL. Please do not confuse
this with the
Sun Community Source
License
, which is not a free software license.
License of xinetd
#xinetd
This is a copyleft free software license, incompatible with the GPL.
It is incompatible because it places extra restrictions on
redistribution of modified versions that contradict the redistribution
requirements in the GPL.
Yahoo! Public License 1.1
#Yahoo
This is a free software license. It has a copyleft similar to the
one found in the Mozilla Public License. It also has a choice of law
clause in section 7. These features both make the license
GPL-incompatible. The license also unfortunately uses the term
intellectual
property
”.
Zend License, Version 2.0
#Zend
This license is used by one part of PHP4. It is a non-copyleft free
software license which is incompatible with the GNU GPL, and has
practical problems
like those of the original BSD license.
We recommend that you not use this license for anything you write.
Zimbra Public License 1.3
#Zimbra
This license is identical to the
Yahoo! Public
License 1.1
, except that the license is provided by VMWare instead
of Yahoo!. Our comments there apply here as well; this is a
GPL-incompatible, partial copyleft free software license.
Zope Public License version 1
#Zope
This is a lax, fairly permissive non-copyleft free software
license with
practical
problems
like those of the original BSD license, including
incompatibility with the
GNU GPL
We urge you not to use the ZPL version 1 for software you write.
However, there is no reason to avoid running programs that have been
released under this license, such as previous versions of Zope.
Version 2.0 of the Zope Public License
is
GPL-compatible.
Nonfree Software Licenses
#NonFreeSoftwareLicenses
The following licenses
do not qualify
as
free software
licenses. A nonfree license is automatically incompatible with the
GNU GPL
Of course, we urge you to avoid using nonfree software licenses, and
to avoid using nonfree programs.
There is no way we could list all the known nonfree software
licenses here; after all, every proprietary software company has its
own. We focus here on licenses that are often mistaken for free
software licenses but are, in fact,
not
free software
licenses.
We have provided links to these licenses when we can do so without
violating our general policy: that we do not make links to sites that
promote, encourage or facilitate the use of nonfree software packages.
The last thing we want to do is give any nonfree program some gratis
publicity that might encourage more people to use it. For the same
reason, we have avoided naming the programs for which a license is used,
unless we think that for specific reasons it won't backfire.
No license
#NoLicense
If source code does not carry a license to give users the four
essential freedoms, then unless it has been explicitly and validly
placed in the public domain, it is not free software.
Some developers think that code with no license is
automatically
in the public domain
. That
is not true under today's copyright law; rather, all copyrightable
works are copyrighted by default. This includes programs. Absent a
license to grant users freedom, they don't have any. In some
countries, users that download code with no license may infringe
copyright merely by compiling it or running it.
In order for a program to be free, its copyright holders must
explicitly grant users the
four
essential freedoms
. The document with which they do so is called
free software license
. This is what free software
licenses are for.
Some countries allow authors to put code in the public domain, but
that requires explicit action which can vary among jurisdictions. In
most cases it is
better to copyleft your code
to assure that freedom reaches all
users of the code.
Code written by employees of the US government is a special
exception, since US copyright law explicitly puts that in the public
domain; but this does not apply to works that the US pays a company to
write. It also does not apply to other countries, many of which do
allow the state to have a copyright on government writings.
Aladdin Free Public License
#Aladdin
Despite its name, this is not a free software license because it
does not allow charging for distribution, and largely prohibits simply
packaging software licensed under it with anything for which a charge
is made.
Anti-996 License
#Anti-996
This is not a free software license. It places
restrictions
on the freedom to use the program for any purpose
Please do not use this license for your own software. We will avoid
using software under this license, as we do all other nonfree software.
Anti-Capitalist Software License
#anticapitalist
The Anti-Capitalist Software License is a
nonfree
license because it extends the four freedoms only to some kinds of
organizations
, not to all. Such a restriction in a software license,
in the name of any cause whatsoever, imposes
too much power over users
. Please don't use this license, and we
urge you to avoid any software that has been released under it.
Apple Public Source License (APSL), version 1.x
#apsl1
Versions 1.0, 1.1 and 1.2 are
not free
software licenses
. Please
don't use these licenses, and we urge you to avoid any software that has
been released under them.
Version 2.0 of the APSL
is a free software license.
Artistic License 1.0
#ArtisticLicense
We cannot say that this is a free software license because it is too
vague; some passages are too clever for their own good, and their meaning is
not clear. We urge you to avoid using it, except as part of
the disjunctive license of Perl
AT&T Public License
#ATTPublicLicense
The AT&T Public License is a nonfree license. It has several
serious problems:
The patent license is voided by any modification, no matter how
small, of the pertinent code.
You must demand a written agreement when you distribute the
sources or patches.
It requires notifying AT&T if you distribute a patch.
Your license can be terminated through no fault of yours, under
section 8/3.
It makes compliance with export control laws a condition
of the license.
Some versions of the license require you to provide support.
Some versions of the license say you cannot sell a copy of the
software for more than the expense of distribution.
The license has two other obnoxious features:
It has a very broad reverse license to AT&T, which goes far beyond
the use of your code, even your code modified.
It asserts one needs a license from AT&T to make a link to their
web site. This is not an immediate practical problem, since the
license says it gives permission to make such a link. (Anyway, people
shouldn't make links to sites about nonfree software.) But such
a claim should not be made or propagated.
Code Project Open License, version 1.02
#cpol
The Code Project Open License is not a free software license.
Section 5.6 restricts how you can use the work. Section 5.4 prohibits
commercial distribution of the software by itself—and depending
on how you read section 3.4, you may not have permission to distribute
the software by itself at all.
Commons Clause
#comclause
The “Commons Clause” is a nonfree license because it
forbids selling copies of the program, and even running the program as
part of implementing any commercial service. Adding insult to injury,
it also twists the words “commons” and “sell.”
We urge people to reject programs under this license and to develop
free replacements. Where a previous version was available as free
software, continuing development of that version is an option.
CNRI Digital Object Repository License Agreement
#DOR
This license is nonfree because of Article 3, which arguably
includes a requirement not to violate the license of
any
program that the user runs—even proprietary programs.
eCos Public License, version 1.1
#eCos11
This was the old license of eCos. It is not a free software
license, because it requires sending every published modified version
to a specific initial developer. There are also some other words in
this license whose meaning we're not sure of that might also be
problematic.
Today
eCos is available
under the GNU GPL with
additional permission for linking with nonfree programs.
The Hippocratic License 1.1
#hippocratic
This is not a free software license, because
it
restricts
what jobs users can use the software for
. That denies freedom 0.
Please don't use this license, and we urge you to avoid any software
that has been released under it.
This entry was previously listed as the First Do No Harm license.
GPL for Computer Programs of the Public Administration
#GPL-PA
The GPL-PA (whose original name in Portuguese is
“Licença Pública Geral para
Administração Pública”) is nonfree for
several reasons:
It permits use only in “normal circumstances”.
It does not allow distribution of source code without binaries.
Its permissions lapse after 50 years.
Please don't use this license, and we urge you to avoid any software
that has been released under it.
Hacktivismo Enhanced-Source Software License Agreement
(HESSLA)
#HESSLA
This is not a free software license, because it
restricts what jobs
people can use the software for, and restricts in substantive ways what
jobs modified versions of the program can do
. Please don't use this
license, and we urge you to avoid any software that has been released
under it.
Jahia Community Source License
#Jahia
The Jahia Community Source License is not a free software license. Use
of the source code is limited to research purposes.
The JSON License
#JSON
This is the license of the original implementation of the JSON data
interchange format. This license uses the Expat license as a base,
but adds a clause mandating: “The Software shall be used for Good, not
Evil.” This is a restriction on usage and thus conflicts with freedom
0. The restriction might be unenforcible, but we cannot presume that.
Thus, the license is nonfree.
Please don't use this license, and we urge you to avoid any
software that has been released under it.
Old license of ksh93
#ksh93
ksh93 used to be shipped with an original license that was not a free
software license. One reason for this is that it required that all changes
be sent to the developer.
License of Lha
#Lha
The lha license must be considered nonfree because it is so vague that
you cannot be sure what permissions you have.
Llama 3.1 Community License Agreement and Llama 3.1 Acceptable Use Policy
#Llama
This is not a free software license.
It denies freedom 0: it imposes an “acceptable use policy” that
prohibits a
series of 25-odd uses
Some of the uses listed in the policy are outrageous, some should be
illegal, and some are already illegal in some places. There is,
however, a crucial difference between prohibitions enacted by
democratically controlled governments in the law and a private company
dictating what we are allowed to do in our lives.
Additionally, the license excludes certain users—those whose
programs or servers are very widely used. (See Sec. 2 titled
“Additional Commercial Terms”). A free software license may not
arbitrarily deny use of the program to anyone.
Another grave flaw in this license is that it requires a user to obey
any and all laws—including trade regulations of other countries
that have no way to enforce them on you in your country. This can have
the effect of
denying freedoms 2 and 3 in some cases
. Even if a country cannot
enforce its trade regulations where you live, it can ask the program's
developer to sue you.
This license was written for use on a Large Language Model
(LLM)—something that generates output by patching together snippets of input
data without understanding what (if anything) the resulting output
means. LLMs (and other machine learning applications) consist of
software and non-software elements, such as model parameters.
Exercising software freedom in machine learning applications is
subject to challenges that go beyond a license. This license certainly
does not resolve these issues, but we do not elaborate about it here,
as the license is nonfree already for reasons stated above.
Microsoft's Shared Source CLI, C#, and Jscript License
#Ms-SS
This license does not permit commercial distribution, and only allows
commercial use under certain circumstances.
Microsoft has other licenses which it describes as “Shared
Source”, some of which have different restrictions. Thus,
“Shared Source” is too vague to draw moral conclusions
from.
Please don't use this license, and we urge you to avoid any software
that has been released under it.
NASA Open Source Agreement
#NASA
The NASA Open Source Agreement, version 1.3, is not a free software
license because it includes a provision requiring changes to be your
“original creation”. Free software development depends on
combining code from third parties, and the NASA license doesn't permit
this.
We urge you not to use this license. In addition, if you are a
United States citizen, please write to NASA and call for the use of a
truly free software license.
Oculus Rift SDK License
#OculusRiftSDK
This is not a free software license; it has several fatal flaws.
One can't redistribute anything less than the whole program libOVR.
One's distribution rights can be terminated on vague conditions.
Those who make modified versions are required to send them to
Oculus on demand.
Use is allowed only with their product.
New license versions totally supplant old versions, which means
that permissions already given can be withdrawn.
There might be additional fatal flaws; after seeing this many,
we stopped looking for more.
Please don't use this license, and we urge you to avoid any software
that has been released under it.
Open Public License
#OpenPublicL
This is not a free software license, because it requires sending
every published modified version to a specific initial developer.
There are also some other words in this license whose meaning we're
not sure of that might also be problematic.
Please don't use this license, and we urge you to avoid any software
that has been released under it.
Peer-Production License
#PPL
The Peer-Production License is not a free software license because
it restricts who can redistribute the program and for what purpose.
It also does not give anyone permission to run the program.
The PPL has several provisions designed specifically for artistic
performances, and we have nothing against its use for art works;
however, people reportedly advocate its use for software too. The PPL
should not be used for software, manuals, or other works that ought to
be free.
Personal Public License Version 3a
#PPL3a
The Personal Public License Version 3a is a nonfree license because it
denies some users (organizations, governments, businesses) the four
freedoms.
License of PINE
#PINE
The license of PINE is not a free software license because it mostly
prohibits the distribution of modified versions. It also restricts the
media that can be used for
selling
copies
Please note that a successor to Pine, Alpine, is released under the
Apache License, version 2.0
Old Plan 9 license
#Plan9
This is not a free software license; it lacks essential freedoms such
as the right to make and use private changes. Of course you should not
use this license, and we urge you to avoid any software that has been
released under it.
A detailed
discussion of this license is also available
In September 2002 it was observed that the published license for
Plan 9 had been modified, adding more restrictions to it, although
its date still said 09/20/00. However, a
further
license change in 2003 made Plan 9 free software
Responsible AI Licenses (“RAIL”)
#RAIL
“RAIL” is a set of licenses designed for source code
and for other works (including non-software elements of machine learning
applications). They are:
AI Pubs Open Rail-M license
AI Pubs Open Rail-S license
Responsible AI END USER LICENSE AGREEMENT
Responsible AI SOURCE CODE License
BigScience Open RAIL-M License
These are nonfree licenses, because they deny freedom 0. They all
contain a similar set of “use restrictions” that prohibit using
the program to do a series of 11-odd jobs.
Licenses that restrict the freedom to run the program are unjust, as
explained in
“Why programs must not limit the freedom to run them”
Some of these uses are outrageous, some should be illegal, and some
are already illegal in some places. To prohibit them is a decision that
must be made democratically; it is never legitimate to allow anyone to impose
decisions about what people are allowed to do with their computers and the
software on them.
Another grave flaw in these licenses is that they require a user to
obey any and all laws—including trade regulations of other countries
that have no way to enforce them on you in your country. This can have the
effect of denying freedoms 2 and 3 (to redistribute unchanged copies and
modified versions) in some cases. Even if a country cannot enforce its
trade regulations where you live, it can bribe or bully the company to
make it sue you.
A secondary disadvantage is that the licenses use biased terminology
that ought to be avoided, including
“intellectual property”
and
“artificial intelligence”
Use of those licenses will tend to promote use of those terms.
Exercising software freedom in machine learning applications is
subject to challenges that go beyond a license. “RAIL” licenses
do not try to deal with these issues.
Reciprocal Public License
#RPL
The Reciprocal Public License is a nonfree license because of three
problems. 1. It puts limits on prices charged for an initial copy.
2. It requires notification of the original developer for
publication of a modified version. 3. It requires publication of
any modified version that an organization uses, even privately.
Scilab license
#Scilab
This is not a free software license because it does not allow
commercial distribution of a modified version. Thankfully, starting
from version 5.0.0, the Scilab software is free software, released
under CeCILL version 2.
Scratch 1.4 license
#Scratch
This is not a free software license because it does not allow
commercial redistribution. In addition, condition 4 substantively
restricts the functionality of modified versions.
Newer versions Scratch software are distributed under the GNU GPL,
but some of those newer version we do not recommend, because they
depend on the proprietary software, Adobe Air.
Simple Machines License
#SML
Despite the name, this is a software license, and it's nonfree
for several reasons:
You must get the licensor's permission before distributing the
software.
You
cannot sell copies of the
software
It's possible that your license can be terminated if you received
the software from someone who did not obey the license's terms.
Source First License, version 1.1
#SFL
This license is also known as the FUTO license.
The Source First License 1.1 is a nonfree license because it
forbids commercial use of the program, and also because it restricts
release of versions with modified functionality.
We urge people to reject programs under this license and to
develop free replacements. Where a previous version was available as
free software, continuing development of that version is an option.
Old Squeak license
#Squeak
The original Squeak license, as applied to software, is not a free
software license because it requires all users in whatever country to
obey US export control laws. As applied to fonts, it also does not
permit modification.
In addition, it has a requirement for users to indemnify the
developer, which is enough to make many users think twice about using it
at all.
Recent versions of Squeak (from 4.0 on) are released under an
Expat-style License
with some portions of the code
under the
Apache License 2.0
Sun Community Source License
#SunCommunitySourceLicense
This is not a free software license; it lacks essential freedoms such
as publication of modified versions. Please don't use this license, and
we urge you to avoid any software that has been released under
it.
Sun Solaris Source Code (Foundation Release) License, Version 1.1
#SunSolarisSourceCode
This is not a free software license. The license prohibits
redistribution, prohibits commercial use of the software, and can be
revoked.
Sybase Open Watcom Public License version 1.0
#Watcom
This is not a free software license. It requires you to publish the
source code publicly whenever you “Deploy” the covered
software, and “Deploy” is defined to include many kinds of
private use.
SystemC “Open Source” License, Version 3.0
#SystemC-3.0
This license requires all recipients to proactively help the licensor
enforce its trademarks. This is an unreasonable condition to place on
users' rights, so the license is nonfree. It also has other practical
problems: some of the requirements are vague, and it uses the term
“intellectual
property”
Despite the name, it is not clear whether this license would
qualify as “open source”. However, our judgment of it is
not based on that.
Truecrypt license 3.0
#Truecrypt-3.0
This license is nonfree for several reasons. It says that if you
don't understand the license you may not use the program. It puts
conditions on allowing others to run your copy. It puts conditions on
separate programs that “depend on” Truecrypt. The
trademark condition applies to “associated materials”.
There are other points in the license which seem perhaps
unacceptable, and in our uncertainty about them we delayed in posting
our evaluation. We have posted it now to explain why we do not mourn
the demise of Truecrypt. There
are
free
programs that do the same job
University of Utah Research Foundation Public License
#UtahPublicLicense
The University of Utah Research Foundation Public License
is a nonfree license because
it does not allow commercial redistribution. It also purports to
restrict commercially running the software and even commercially giving
consultation about it. Those restrictions are probably not legally
enforceable under US copyright law, but they might be in some countries;
even asserting them is outrageous.
The use of this license by the University of Utah exemplifies a
dangerous
trend for universities to restrict knowledge
rather than
contributing it to the public.
If a university tries to impose a license like this on the software
you are writing, don't give up hope.
With persistence
and firmness, and some forethought, it is possible to prevail over
money-grabbing university administrators.
The earlier you raise the issue, the better.
YaST License
#YaST
This is not a free software license. The license prohibits
distribution for a fee, and that makes it impossible for the software to
be included in the many CD-ROM free software collections that are sold
by companies and by organizations.
There may be another problem in section 2a, but a word seems to be
missing there, so it is hard to be sure what meaning is really
intended.
(The YaST software itself no longer uses this nonfree YaST license;
happily, it is now free software, released under the GNU GPL.)
Licenses For Documentation
Free Documentation Licenses
#FreeDocumentationLicenses
The following licenses qualify as
free
documentation
licenses.
GNU Free Documentation License
#FDL
This is a license intended for use on
copylefted
free documentation
. We
plan to
adopt it
for all GNU
manuals. It is also suitable for other kinds of useful works (such as
textbooks and dictionaries, for instance). Its applicability is not
limited to textual works (“books”).
FreeBSD Documentation License
#FreeBSDDL
This is a permissive non-copyleft free documentation license that is
compatible with the GNU FDL.
Apple's Common Documentation License, Version 1.0
#ACDL
This is a free documentation license that is incompatible with the
GNU FDL. It is incompatible because Section (2c) says “You
add no other terms or conditions to those of this License”, and
the GNU FDL has additional terms not accounted for in the Common
Documentation License.
Open Publication License, Version 1.0
#OpenPublicationL
This license
can
be used as a free documentation
license. It is a copyleft free documentation license
provided
the copyright holder does not exercise any of
the “LICENSE OPTIONS” listed in Section VI of the license.
But if either of the options is invoked, the license becomes
nonfree. In any case, it is incompatible with the GNU FDL.
This creates a practical pitfall in using or recommending this
license: if you recommend “Use the Open Publication License, Version
1.0 but don't enable the options”, it would be easy for the second
half of that recommendation to get forgotten; someone might use the
license with the options, making a manual nonfree, and yet think he
or she is following your advice.
Likewise, if you use this license without either of the options to
make your manual free, someone else might decide to imitate you, then
change his or her mind about the options thinking that that is just a
detail; the result would be that his or her manual is nonfree.
Thus, while manuals published under this license do qualify as free
documentation if neither license option was used, it is better to use the
GNU Free Documentation License and avoid the risk of leading someone else
astray.
Please note that this license is not the same as the
Open Content License
. These two licenses are frequently
confused, as the Open Content License is often referred to as the
“OPL”. For clarity, it is better not to use the
abbreviation “OPL” for either license. It is worth spelling
their names in full to make sure people understand what you say.
Nonfree Documentation Licenses
#NonFreeDocumentationLicenses
The following licenses
do not qualify
as free documentation licenses:
Open Content License, Version 1.0
#OpenContentL
This license does not qualify as free, because there are restrictions on
charging money for copies. We recommend you do not use this license.
Please note that this license is not the same as the
Open Publication License
. The practice of
abbreviating “Open Content License” as “OPL”
leads to confusion between them. For clarity, it is better not to use
the abbreviation “OPL” for either license. It is worth
spelling their names in full to make sure people understand what you
say.
Creative Commons NonCommercial, any version
#CC-BY-NC
This license does not qualify as free, because there are
restrictions on charging money for copies. Thus, we recommend you do
not use this license for documentation.
In addition, it has a drawback for any sort of work: when a
modified version has many authors, in practice getting permission for
commercial use from all of them would become infeasible.
Creative Commons Noderivatives, any version
#CC-BY-ND
This license does not qualify as free, because there are
restrictions on distributing modified versions. We recommend you do
not use this license for documentation.
Licenses for Other Works
Licenses for Works of Practical Use
besides Software and Documentation
#OtherLicenses
GNU General Public License
#GPLOther
The GNU GPL
can
be used for general data which is
not software, as long as one can determine what the definition of
“source code” refers to in the particular case. As it turns
out, the DSL (see below) also requires that you determine what the
“source code” is, using approximately the same definition
that the GPL uses.
GNU Free Documentation License
#FDLOther
The GNU FDL is recommended for textbooks and teaching materials for
all topics. (“Documentation” simply means textbooks and
other teaching materials for using equipment or software.) We also
recommend the GNU FDL for dictionaries, encyclopedias, and any other
works that provide information for practical use.
CC0 1.0 Universal
#CC0
CC0 is a public domain dedication from Creative Commons. A
work released under CC0 is dedicated to the public domain to the
fullest extent permitted by law. If that is not possible for any
reason, CC0 also provides a lax, permissive license as a fallback.
Both public domain works and the lax license provided by CC0 are
compatible with the GNU GPL.
If you want to release your non-software work to the public domain, we
recommend you use CC0. For works of software it is not recommended, as
CC0 has a term expressly stating it does not grant you any patent licenses.
Because of this lack of patent grant, we encourage you to be careful
about using software under this license; you should first consider
whether the licensor might want to sue you for patent infringement. If
the developer is refusing users patent licenses, the program is in
effect a trap for users and users should avoid the program.
Creative Commons Attribution 4.0 license
(a.k.a. CC BY)
#ccby
This is a non-copyleft free license that is good for art and
entertainment works, and educational works. It is compatible with all
versions of the GNU GPL; however, like all CC
licenses,
it
should
not be used on software
#which-cc
Creative Commons publishes many licenses which are
very different. Therefore, to say that a work “uses a Creative
Commons license” is to leave the principal questions about the
work's licensing unanswered. When you see such a statement in a work,
please ask the author to change the work to state clearly and
visibly
which
of the Creative Commons license it uses. And if
someone proposes to “use a Creative Commons license” for a
certain work, it is vital to ask “Which Creative Commons
license?” before proceeding any further.
Creative Commons Attribution-Sharealike 4.0 license
(a.k.a. CC BY-SA)
#ccbysa
This is a copyleft free license that is good for artistic and
entertainment works, and educational works. Like all CC
licenses,
it
should
not be used on software
CC BY-SA 4.0 is one-way compatible with the GNU GPL version 3: this
means you may license your modified versions of CC BY-SA 4.0 materials
under GNU GPL version 3, but you may not relicense GPL 3 licensed
works under CC BY-SA 4.0.
Because Creative Commons lists only version 3 of the GNU GPL on its
compatible
licenses
list, it means that you can not license your adapted CC
BY-SA works under the terms of “GNU GPL version 3, or (at your option)
any later version.” However, Section 14 of the GNU GPL version 3
allows licensors to specify a proxy to determine whether future
versions of the GNU GPL can be used. Therefore, if someone adapts a CC
BY-SA 4.0 work and incorporates it into a GNU GPL version 3 licensed
project,
they
can specify Creative Commons as their proxy
(via
so that if and when Creative Commons determines that a future version
of the GNU GPL is a compatible license, the adapted and combined work
could be used under that later version of the GNU GPL.
Please
be specific about which Creative
Commons license is being used
Design Science License (DSL)
#dsl
This is a free and copyleft license meant for general data.
Please don't use it for software or documentation, since it is
incompatible with the GNU GPL and with the GNU FDL; however, it is
fine to use for other kinds of data.
Free Art License
#FreeArt
This is a free and copyleft license meant for artistic works. It
permits commercial distribution, as any free license must. It is a
copyleft license because any larger work that includes part of the
work you received must be released, as a whole, either under the same
license or under a similar license that meets stated criteria. Please
don't use it for software or documentation, since it is incompatible
with the GNU GPL and with the GNU FDL.
Open Database license
#ODbl
This is a free and copyleft license meant for data. It is
incompatible with the GNU GPL. Please don't use it for software or
documentation, since it is incompatible with the GNU GPL and with the
GNU FDL. It makes inconvenient requirements about signing contracts
which try to create an effect like copyleft for data that is not
copyrightable, so we don't recommend using it; however, there is no
reason to avoid using data released this way.
Licenses for Fonts
#Fonts
The licenses below apply to an instantiation of a design in a computer
file, not the artistic design. As far as we know, an implementation of
a design is always copyrightable. The legal status of the artistic
design is complex, and varies by jurisdiction.
GNU General Public License
#GPLFonts
The GNU GPL
can
be used for fonts. However, note
that it does not permit embedding the font in a document unless that
document is also licensed under the GPL. If you want to allow this, use
the
font
exception
. See also this
explanatory
essay about the GPL Font Exception
Arphic Public License
#Arphic
This is a copyleft free software license, incompatible with the
GPL. Its normal use is for fonts, and in that use, the
incompatibility does not cause a problem.
License
of the ec fonts for LaTeX
#ecfonts
This license covers the European Computer Modern Fonts and Text
Companion Fonts, commonly used with LaTeX. Depending on how it is
used, it may be free or not. If the package says that some fonts in
the package may not be modified, then the package is nonfree.
Otherwise the package is free. The original fonts have no
restrictions on modification, so they are free.
Much like
the LaTeX Project Public
License 1.2
, this license requires modified versions of the work
to use a name that's different from the name of any prior version.
This is acceptable for work meant to be used with LaTeX, since TeX
allows you to create filename mappings for your programs, but it's
very annoying and could be overly burdensome in other contexts.
IPA
Font License
#IPAFONT
This is a copyleft free software license, incompatible with the
GPL. It has an unfortunate condition requiring that derivative works
not use or include the name of the original work as a program name,
font name or file name. This is acceptable for fonts as fonts can be
aliased or renamed using free software tools, but it's very annoying
and could be overly burdensome in other contexts.
SIL Open Font License 1.1
#SILOFL
The Open Font License (including its original release, version 1.0)
is a free copyleft license for fonts. Its only unusual requirement is
that when selling the font, you must redistribute it bundled with
some software, rather than alone. Since a simple Hello World program
will satisfy the requirement, it is harmless. Neither we nor SIL
recommend the use of this license for anything other than
fonts.
Licenses for Works stating a Viewpoint (e.g., Opinion or Testimony)
#OpinionLicenses
Works that express someone's opinion—memoirs, editorials, and
so on—serve a fundamentally different purpose than works for
practical use like software and documentation. Because of this, we
expect them to provide recipients with a different set of permissions:
just the permission to copy and distribute the work verbatim.
Richard Stallman discusses this
frequently
in his speeches.
Because so many licenses meet these criteria, we cannot list them
all. If you are looking for one to use yourself, however, there are
two that we recommend:
GNU Verbatim Copying License
#GNUVerbatim
This was the license used throughout the GNU web site for many
years. It is very simple, and especially well-suited to written
works.
Creative Commons Attribution-NoDerivs 4.0 license
(a.k.a. CC BY-ND)
#ccbynd
This is the license used throughout the GNU and FSF web sites.
This license provides much the same permissions as our verbatim
copying license, but it's much more detailed. We particularly
recommend it for audio and/or video works of opinion. Previous
versions of this license are also OK to use, but we do recommend
upgrading to this version if you can. Please
be
specific about which Creative Commons license is being
used
Licenses for Designs for Physical Objects
#Designs
Circuits are meant for practical use, so circuit designs should carry
a free license. We recommend releasing them under the GNU General
Public License, version 3 or later. Version 3 was designed for such
use.
3D-printer plans for objects meant for practical use should also be
free. We recommend the GNU GPL or one of the Creative Commons licenses
that are free such as CC-BY or CC-BY-SA.
3D-printer plans for decorative objects are artistic works; any of the
Creative Commons licenses is ok for them.
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