Various Licenses and Comments about Them - GNU Project - Free Software Foundation (FSF)@import url('/print.css'); Skip to content | Translations of this page Search: The GNU Operating System Home Store History Philosophy Licenses Download GNU Help GNU Sitemap Various Licenses and Comments about ThemTable of Contents Introduction Software Licenses GPL-Compatible Free Software Licenses GPL-Incompatible Free Software Licenses Non-Free Software Licenses Licenses For Documentation Free Documentation Licenses Non-Free Documentation Licenses Licenses for Works of Practical Use Besides Software and Documentation Licenses for Fonts Licenses for Works of Opinion and JudgmentIntroductionWe classify a license according to certain key questions: 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.If you want help choosing a license, evaluating a license, or haveany other questions about licenses, you can email us at <licensing@fsf.org>.If you are contemplating writing a new license, please contact theFSF by writing to <licensing@fsf.org>. Theproliferation of different free software licenses means increased workfor users in understanding the licenses; we may be able to help you findan existing free software license that meets your needs. We try to listthe most commonly encountered free software license on this page, butcannot list them all; we'll try our best to answer questions about freesoftware licenses whether or not they are listed here. The licenses aremore or less in alphabetical order within each section.If that isn't possible, if you really need a new license, with ourhelp you can ensure that the license really is a Free Software licenseand avoid various practical problems.By the way, if you believe you have found a violation of one of ourlicenses, please refer toour license violation page.Software Licenses GPL-Compatible Free Software LicensesThe following licenses qualify as free softwarelicenses, and are compatible with the GNUGPL. GNU General Public License (GPL) version 3This is the latest version of the GNU GPL: a free software license, anda 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 laterversions of the GPL as well. When this is the case, you can use thecode under GPLv3 to make the desired combination. GNU General Public License (GPL) version 2This is the previous version of the GNU GPL: a free software license, anda copyleft license. We recommend the latest versionfor 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 laterversions of the GPL as well. When this is the case, you can use thecode under GPLv3 to make the desired combination. GNU Lesser General Public License (LGPL) version 3This is the latest version of the LGPL: a free software license, but nota strong copyleft license, because it permits linking with non-freemodules. It is compatible with GPLv3. We recommend it for special circumstancesonly.Please note that LGPLv3 is not compatible with GPLv2 by itself. However,most software released under GPLv2 allows you to use the terms of laterversions of the GPL as well. When this is the case, you can use thecode under GPLv3 to make the desired combination. GNU Lesser General Public License (LGPL) version 2.1This is the previous version of the LGPL: a free software license, butnot a strong copyleft license, because it permits linking with non-freemodules. It is compatible with GPLv2 and GPLv3. We generally recommend the latest version of the LGPL, for special circumstances only.GNU Affero General PublicLicense (AGPL) version 3This is a free software, copyleft license. Its terms effectivelyconsist of the terms of GPLv3, with an additional paragraph in section 13to allow users who interact with the licensed software over a network toreceive the source for that program. We recommend that developers considerusing the GNU AGPL for any software which will commonly be run over anetwork.Please note that the GNU AGPL is not compatible with GPLv2. It is alsotechnically not compatible with GPLv3 in a strict sense: you cannot takecode released under the GNU AGPL and use it under the terms of GPLv3, orvice versa. However, you are allowed to combine separate modules or sourcefiles released under both of those licenses in a single project, which willprovide many programmers with all the permission they need to make theprograms they want. See section 13 of both licenses for details. Apache License, Version 2.0This is a free software license, compatible with version 3 of the GPL.Please note that this license is not compatible with GPL version 2, becauseit has some requirements that are not in the older version. These includecertain patent termination and indemnification provisions.ArtisticLicense 2.0This license is a free software license, compatible with the GPLthanks to the relicensing option in section 4(c)(ii). Clarified Artistic LicenseThis license is a free software license, compatible with the GPL. Itis the minimal set of changes needed to correct the vagueness of the Artistic License 1.0. Berkeley Database License (aka the Sleepycat Software Product License)This is a free software license, compatible with the GNU GPL. Boost Software LicenseThis is a simple, permissive non-copyleft free software license,compatible with the GNU GPL. Modified BSD license(Note: on the preceding link, the modified BSD license islisted in the General section.)This is the original BSD license, modified by removal of theadvertising clause. It is a simple, permissive non-copyleft freesoftware license, compatible with the GNU GPL.If you want a simple, permissive non-copyleft free software license,the modified BSD license is a reasonable choice. However, it is riskyto recommend use of “the BSD license”, because confusioncould easily occur and lead to use of the flawed original BSD license. To avoid thisrisk, you can suggest the X11 license instead. The X11 license and therevised BSD license are more or less equivalent.This license is sometimes referred to as the 3-clause BSD license. CeCILL version 2The CeCILL is a free software license, explicitly compatible with theGNU GPL. The text of the CeCILL uses a couple of biased terms that ought to beavoided: “intellectual property” (see this article) and“protection” (see this article); this decisionwas unfortunate, because reading the license tends to spread thepresuppositions of those terms. However, this does not cause anyparticular problem for the programs released under the CeCILL.Section 9.4 of the CeCILL commits the program's developers to certainforms of cooperation with the users, if someone attacks the programwith 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 inthose ways anyway, then it isn't a problem for you.The Clear BSD LicenseThis 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 disclaiming patent licenses to set up a trap for you, it would be wise to avoid the program. Cryptix General LicenseThis is a simple, permissive non-copyleft free software license,compatible with the GNU GPL. It is very similar to the X11 license. eCos license version 2.0The eCos license version 2.0 is a GPL-compatible free softwarelicense. It consists of the GPL, plus an exception allowing linking tosoftware not under the GPL. This license has the same disadvantagesas the LGPL.Educational Community License 2.0This 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 2This is a free software license, compatible with the GNU GPL. Previousreleases of the Eiffel license are not compatible with theGPL. EU DataGrid Software LicenseThis is a simple, permissive non-copyleft free software license,compatible with the GNU GPL. Expat LicenseThis is a simple, permissive non-copyleft free software license,compatible with the GNU GPL. It is sometimes ambiguously referred to asthe MIT License. FreeBSD licenseThis is the original BSD license with the advertising clause andanother clause removed. (It is also sometimes called the“2-clause BSD license”.) It is a simple, permissivenon-copyleft free software license, compatible with the GNU GPL.If you want a simple, permissive non-copyleft free software license,the FreeBSD license is a reasonable choice. However, please don't callit a “BSD” or “BSD-style” license, because thatis likely to cause confusion which could lead to use of the flawed original BSD license. Freetype Project LicenseThis is a free software license, and compatible with GPLv3. It has some attribution requirements which make it incompatible with GPLv2.License of the iMatix Standard Function LibraryThis is a free software license and is GPL compatible.Independent JPEG Group LicenseThis 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.License of imlib2This 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. Intel Open Source LicenseThis is a Free Software license, compatible with the GNU GPL.ISC LicenseThis license is sometimes also known as the OpenBSD License. It is a free software license, and compatible with the GNU GPL.This license does have an unfortunate wording choice: it provides recipients with "Permission to use, copy, modify, and distribute this software...." This is 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. Thus, 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.Microsoft Public License (Ms-PL)This is a free software license, compatible with version 3 of the GNU GPL. It is incompatible with version 2 of the GNU GPL because of the conditions in sections 3(B) and 3(C).Please do not use this license for anything you write; there are already well-known free software licenses that serve the same purpose, such as the Apache License version 2.0, and we must all stand together to combat license proliferation. However, there is no reason to avoid using software released under this license. NCSA/University of Illinois Open Source LicenseThis license is based on the terms of the Expatand modified BSD licenses. It is a simple,permissive non-copyleft free software license, compatible with the GNUGPL.License of Netscape JavascriptThis is the disjunction of the Netscape PublicLicense and the GNUGPL. Because of that, it is a free software license, compatiblewith the GNU GPL, but not a strong copyleft.This disjunctive license is a good choice if you want to make yourpackage GPL-compatible and MPL-compatible. However, you can alsoaccomplish that by using the LGPL or the Guile license.Such a disjunctive license might be a good choice if you have beenusing the MPL, and want to change to a GPL-compatible license withoutsubtracting any permission you have given for previous versions. OpenLDAP License, Version 2.7This is a permissive non-copyleft free software license that iscompatible with the GNU GPL.License of Perl 5 and belowThis 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 freesoftware license, but it may not be a real copyleft. It is compatiblewith the GNU GPLbecause the GNU GPL is one of the alternatives.We recommend you use this license for any Perl 4 or Perl 5 packageyou write, to promote coherence and uniformity in Perl programming.Outside of Perl, we urge you not to use this license; it is better touse just the GNU GPL.Public DomainBeing in the public domain is not a license; rather, it means thematerial is not copyrighted and no license is needed. Practicallyspeaking, though, if a work is in the public domain, it might as wellhave an all-permissive non-copyleft free software license. Publicdomain material is compatible with the GNU GPL. License of Python 2.0.1, 2.1.1, and newer versionsThis 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 versionsThis is a free software license and is compatible with the GNU GPL.Please note, however, that newer versions of Python are under otherlicenses (see above and below). License of RubyThis is a free software license, compatible with the GPL via anexplicit dual-licensing clause.Standard ML of New Jersey Copyright LicenseThis is a simple, permissive non-copyleft free software license,compatible with the GNU GPL. License of Vim, Version 6.1 or laterThis is a free software license, partially copyleft but notreally. It is compatible with the GPL, by an explicit conversionclause. W3C Software Notice and LicenseThis is a free software license and is GPL compatible. X11 License This is a simple, permissive non-copyleft free software license,compatible with the GNU GPL. Older versions of XFree86 used the samelicense, and some of the current variants of XFree86 also do. Laterversions of XFree86 are distributed under the XFree86 1.1 license.This license is sometimes called the MIT license, but thatterm is misleading, since MIT has used many licenses forsoftware.XFree86 1.1 LicenseThis is a simple, 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 thedistribution that contain acknowledgements.There are currently several variants of XFree86, and only some ofthem use this license. Some continue to use the X11 license. License of ZLibThis is a free software license, and compatible with the GPL. Zope Public License, versions 2.0 and 2.1This is a simple, permissive non-copyleft free software licensewhich is compatible with the GNU GPL. GPL-Incompatible Free Software LicensesThe following licensesare free software licenses, butare notcompatible with the GNU GPL. Affero General Public License version 1The 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 3.0The Academic Free License is a free software license, not copyleft, andincompatible with the GNU GPL. Recent versions contain contract clausessimilar to the Open Software License, and should beavoided for the same reasons. Apache License, Version 1.1This is a permissive non-copyleft free software license. It has a fewrequirements that render it incompatible with the GNU GPL, such as strongprohibitions on the use of Apache-related names. Apache License, Version 1.0This is a simple, permissive non-copyleft free software license with anadvertising clause. This creates practical problems likethose of the original BSD license, including incompatibility with the GNUGPL. Apple Public Source License (APSL), version 2This is a free software license, incompatible with the GNU GPL. Werecommend that you not use this license for new software that you write,but it is ok to use and improve the software released under thislicense. Moreexplanation.BitTorrent Open Source LicenseThis is a free software license, but incompatible with the GPL, for the same reasons as the Jabber Open Source License. Original BSD license(Note: on the preceding link, the original BSD license is listed inthe UCB/LBL section. This license is also sometimes called the“4-clause BSD license”.)This is a simple, permissive non-copyleft free software license witha serious flaw: the “obnoxious BSD advertising clause”. Theflaw is not fatal; that is, it does not render the software non-free.But it does cause practical problems,including incompatibility with the GNU GPL.We urge you not to use the original BSD license for software youwrite. If you want to use a simple, permissive non-copyleft freesoftware license, it is much better to use the modified BSD license or the X11 license.However, there is no reason not to use programs that have been releasedunder the original BSD license. Common Development and Distribution License (CDDL)This is a free software license. It has a copyleft with a scope that'ssimilar to the one in the Mozilla Public License, which makes itincompatible with the GNU GPL. This meansa module covered by the GPL and a module covered by the CDDL cannot legallybe linked together. We urge you not to use the CDDL for this reason.Also unfortunate in the CDDL is its use of the term “intellectualproperty”.Common Public Attribution License 1.0 (CPAL)This is a free software license. It is based on the Mozilla Public License, 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 1.0This is a free software license. Unfortunately, it has a choice of lawclause which makes it incompatible with the GNU GPL. Condor Public LicenseThis is a free software license. It has a couple of requirements thatmake it incompatible with the GNU GPL, including strong restrictions on theuse of Condor-related names, and a condition that you must comply withUnited States export laws. Eclipse Public License Version 1.0The Eclipse Public License is similar to the Common Public License, and ourcomments on the CPL apply equally to the EPL. The only change is thatthe EPL removes the broader patent retaliation language regarding patentinfringement suits specifically against Contributors to the EPL'dprogram. IBM Public License, Version 1.0This is a free software license. Unfortunately, it has a choice of lawclause which makes it incompatible with the GNU GPL. Interbase Public License, Version 1.0This is a free software license that is essentially the same as theMozilla Public License, Version 1.1. Like the MPL, the IPL has somecomplex restrictions that make it incompatible with the GNU GPL. Thatis, a module covered by the GPL and a module covered by the IPL cannotlegally be linked together. We urge you not to use the IPL for thisreason.Jabber Open Source License, Version 1.0The license is a free software license, incompatible with the GPL.It permits relicensing under a certain class of licenses, those whichinclude all the requirements of the Jabber license. The GPL is not amember of that class, so the Jabber license does not permit relicensingunder the GPL. Therefore, it is not compatible. LaTeX Project Public License 1.3aWe have not written a full analysis of this license, but it is a freesoftware license, with less stringent requirements on distribution thanLPPL 1.2 (described next). It is still incompatible with the GPLbecause some modified versions must include a copy of or pointer to anunmodified version. LaTeX Project Public License 1.2This license is an incomplete statement of the distribution termsfor LaTeX. As far as it goes, it is a free software license, butincompatible with the GPL because it hasmany requirements that are not in the GPL.This license contains complex and annoying restrictions on how topublish a modified version, including one requirement that falls justbarely on the good side of the line of what is acceptable: that anymodified file must have a new name.The reason this requirement is acceptable for LaTeX is that TeX hasa facility to allow you to map file names, to specify “use filebar when file foo is requested”. With this facility, therequirement is merely annoying; without the facility, the samerequirement would be a serious obstacle, and we would have to concludeit makes the program non-free.The LPPL says that some files, in certain versions of LaTeX, may haveadditional restrictions, which could render them non-free. For thisreason, it may take some careful checking to produce a version ofLaTeX that is free software.The LPPL makes the controversial claim that simply having files on amachine where a few other people could log in and access them initself constitutes distribution. We believe courts would not upholdthis 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)This is a free software license, but it is incompatible with the GNU GPLbecause of its choice of law clause. We recommend that you not use thislicense for new software that you write, but it is ok to use and improvePlan 9 under this license.Microsoft Reciprocal License (Ms-RL)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-RL for this reason. Mozilla Public License (MPL)This is a free software license which is not a strong copyleft;unlike the X11 license, it has some complexrestrictions that make it incompatible with the GNU GPL. That is, amodule covered by the GPL and a module covered by the MPL cannot legallybe linked together. We urge you not to use the MPL 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 partof a program allows the GNU GPL as an alternate choice, or any otherGPL-compatible license as an alternate choice, that part of the programhas a GPL-compatible license. Netizen Open Source License (NOSL), Version 1.0This is a free software license that is essentially the same as theMozilla Public License, Version 1.1. Like the MPL, the NOSL has somecomplex restrictions that make it incompatible with the GNU GPL. Thatis, a module covered by the GPL and a module covered by the NOSL cannotlegally be linked together. We urge you not to use the NOSL for thisreason. Netscape Public License (NPL), versions 1.0 and 1.1This is a free software license, not a strong copyleft, andincompatible with the GNU GPL. It consists of the Mozilla PublicLicense with an added clause that permits Netscape to use your addedcode even in their proprietary versions of the program. Ofcourse, they do not give you permission to use theircode in the analogous way. We urge you not to use the NPL. Nokia Open Source LicenseThis is similar to the Mozilla Public License: a freesoftware license incompatible with the GNU GPL.Old OpenLDAP License, Version 2.3This is a permissive non-copyleft free software license with a fewrequirements (in sections 4 and 5) that render it incompatible withthe GNU GPL. Note that the latest version of OpenLDAP hasa different license that is compatible withthe GNU GPL.We urge you not to use the older OpenLDAP license for software youwrite. However, there is no reason to avoid running programs that havebeen released under this license. Open Software License, all versions through 3.0The Open Software License is a free software license. It isincompatible with the GNU GPL in several ways.Recent versions of the Open Software License havea term which requires distributors to try to obtain explicit assent tothe license. This means that distributing OSL software on ordinary FTPsites, sending patches to ordinary mailing lists, or storing thesoftware in an ordinary version control system, is arguably a violationof the license and would subject you to possible termination of thelicense. Thus, the Open Software License makes it very difficult todevelop software using the ordinary tools of free software development.For this reason, and because it is incompatible with the GPL, werecommend that no version of the OSL be used for any software.We urge you not to use the Open Software License for software youwrite. However, there is no reason to avoid running programs thathave been released under this license. OpenSSL licenseThe license of OpenSSL is a conjunction of two licenses, one of thembeing the license of SSLeay. You must follow both. The combinationresults in a copyleft free software license that is incompatible withthe GNU GPL. It also has an advertising clause like the original BSDlicense and the Apache license.We recommend using GNUTLS instead of OpenSSL in software you write.However, there is no reason not to use OpenSSL and applications thatwork with OpenSSL. Phorum License, Version 2.0This is a free software license but it is incompatible with the GPL. Section 5 makesthe license incompatible with the GPL. PHP License, Version 3.01This license is used by most of PHP4. It is a non-copyleft freesoftware license. It is incompatible with the GNU GPL because itincludes strong restrictions on the use of “PHP” in thename of derived products.We recommend that you not use this license for anything except PHPadd-ons. License of Python 1.6b1 through 2.0 and 2.1This is a free software license but is incompatible with the GNU GPL.The primary incompatibility is that this Python license is governed by thelaws of the State of Virginia, in the USA, and the GPL does not permitthis. Q Public License (QPL), Version 1.0This is a non-copyleft free software license which is incompatible withthe GNU GPL. It also causes major practical inconvenience, because modifiedsources 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 isnow also released under the GNU GPL.Since the QPL is incompatible with the GNU GPL, you cannot take aGPL-covered program and QPL-covered program and link them together, nomatter 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 yourprogram 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 theprogram. Add it in the source files, after the notice that saysthe program is covered by the GNU GPL.RealNetworksPublic Source License (RPSL), Version 1.0The RPSL is a free software license that is GPL-incompatible for anumber of reasons: it requires that derivative works be licensed under theterms of the RPSL, and mandates that any litigation take place in Seattle,Washington. Sun Industry Standards Source License 1.0This is a free software license, not a strong copyleft, which isincompatible with the GNU GPL because of details rather than anymajor policy. Sun Public LicenseThis is essentially the same as the Mozilla Public License: a freesoftware license incompatible with the GNU GPL. Please do not confusethis with the Sun Community SourceLicense which is not a free software license. License of xinetdThis is a copyleft free software license, incompatible with the GPL.It is incompatible because it places extra restrictions onredistribution of modified versions that contradict the redistributionrequirements in the GPL.Zend License, Version 2.0This license is used by one part of PHP4. It is a non-copyleft freesoftware license which is incompatible with the GNU GPL, and has practical problemslike those of the original BSD license.We recommend that you not use this license for anything you write. Zope Public License version 1This is a simple, fairly permissive non-copyleft free softwarelicense with practicalproblems like those of the original BSD license, includingincompatibility 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 beenreleased under this license, such as previous versions of Zope.Version 2.0 of the Zope Public License isGPL-compatible.Non-Free Software LicensesThe following licenses do not qualify as free softwarelicenses. A non-free license is automatically incompatible with the GNU GPL.Of course, we urge you to avoid using non-free software licenses, andto avoid non-free software in general.There is no way we could list all the known non-free softwarelicenses here; after all, every proprietary software company has itsown. We focus here on licenses that are often mistaken for freesoftware licenses but are, in fact, not free softwarelicenses.We have provided links to these licenses when we can do so withoutviolating our general policy: that we do not make links to sites thatpromote, encourage or facilitate the use of non-free software packages.The last thing we want to do is give any non-free program some gratispublicity that might encourage more people to use it. For the samereason, we have avoided naming the programs for which a license is used,unless we think that for specific reasons it won't backfire.Aladdin Free Public LicenseDespite its name, this is not a free software license because itdoes not allow charging for distribution, and largely prohibits simplypackaging software licensed under it with anything for which a chargeis made. Apple Public Source License (APSL), version 1.xVersions 1.0, 1.1 and 1.2 are not freesoftware licenses (follow the link for more explanation). Pleasedon't use these licenses, and we urge you to avoid any software that hasbeen released under them. Version 2.0 of the APSLis a free software license.Artistic License 1.0We cannot say that this is a free software license because it is toovague; some passages are too clever for their own good, and their meaning isnot clear. We urge you to avoid using it, except as part ofthe disjunctive license of Perl.AT&T Public LicenseThe AT&T Public License is a non-free license. It has severalserious problems:The patent license is voided by any modification, no matter howsmall, of the pertinent code.You must demand a written agreement when you distribute thesources or patches.It requires notifying AT&T if you distribute a patch.Your license can be terminated through no fault of yours, undersection 8/3.It makes compliance with export control laws a conditionof the license.Some versions of the license require you to provide support.Some versions of the license say you cannot sell a copy of thesoftware 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 beyondthe use of your code, even your code modified.It asserts one needs a license from AT&T to make a link to theirweb site. This is not an immediate practical problem, since thelicense says it gives permission to make such a link. (Anyway, peopleshouldn't make links to sites about non-free software.) But sucha claim should not be made or propagated.eCos Public License, version 1.1This was the old license of eCos. It is not a free softwarelicense, because it requires sending every published modified versionto a specific initial developer. There are also some other words inthis license whose meaning we're not sure of that might also beproblematic.Today eCos is available under the GNU GPL withadditional permission for linking with non-free programs. GPL for Computer Programs of the Public AdministrationThe GPL-PA (whose original name in Portuguese is“Licença Pública Geral paraAdministração Pública”) is non-free forseveral reasons:It permits use only in “normal circumstances”.It does not allow distribution of source code without binaries.Its permissions lapse after 50 years. Hacktivismo Enhanced-Source Software License Agreement (HESSLA)This is not a free software license, because it restricts what jobspeople can use the software for, and restricts in substantive ways whatjobs modified versions of the program can do. Jahia Community Source LicenseThe Jahia Community Source License is not a free software license. Useof the source code is limited to research purposes.Old license of ksh93ksh93 used to be shipped with an original license that was not a freesoftware license. One reason for this is that it required that all changesbe sent to the developer.ksh93 is now released under the CommonPublic License. License of LhaThe lha license must be considered non-free because it is so vague thatyou cannot be sure what permissions you have.Microsoft Limited Public License (Ms-LPL)This license is non-free because of section 3(F), which requires that any modified software you make from the original code must run on Windows. The Microsoft Public License does not have this restriction.Microsoft Limited Reciprocal License (Ms-LRL)This license is non-free because of section 3(G), which requires that any modified software you make from the original code must run on Windows. The Microsoft Reciprocal License does not have this restriction.Microsoft Reference LicenseThis is a non-free license: you are not allowed to modify the software at all, and you are only allowed to share it under very particular circumstances. Microsoft's Shared Source CLI, C#, and Jscript LicenseThis license does not permit commercial distribution, and only allowscommercial use under certain circumstances.Microsoft has other licenses which it describes as “SharedSource”, some of which have different restrictions.Microsoft Windows Embedded CE 6.0 Shared Source LicenseThis license is non-free because it places various limitations on the kinds of modifications you can make. For example, your modified software must run on Wince, and you are required to provide end user support for your software. NASA Open Source AgreementThe NASA Open Source Agreement, version 1.3, is not a free softwarelicense because it includes a provision requiring changes to be your“original creation”. Free software development depends oncombining code from third parties, and the NASA license doesn't permitthis.We urge you not to use this license. In addition, if you are aUnited States citizen, please write to NASA and call for the use of atruly free software license. Open Public LicenseThis is not a free software license, because it requires sendingevery published modified version to a specific initial developer.There are also some other words in this license whose meaning we'renot sure of that might also be problematic.License of PINEThe license of PINE is not a free software license because it mostlyprohibits the distribution of modified versions. It also restricts themedia that can be used for sellingcopies.Please note that a successor to Pine, Alpine, is released under the Apache License, version 2.0.Old Plan 9 licenseThis is not a free software license; it lacks essential freedoms suchas the right to make and use private changes. Of course you should notuse this license, and we urge you to avoid any software that has beenreleased under it. A detaileddiscussion of this license is also available.In September 2002 it was observed that the published license forPlan 9 had been modified, adding more restrictions to it, althoughits date still said 09/20/00. However, a furtherlicense change in 2003 made Plan 9 free software. Reciprocal Public LicenseThe Reciprocal Public License is a non-free license because of threeproblems. 1. It puts limits on prices charged for an initial copy.2. It requires notification of the original developer forpublication of a modified version. 3. It requires publication ofany modified version that an organization uses, even privately.Scilab licenseThis is not a free software license because it does notallow commercial distribution of a modified version. SGI Free Software License B, version 1.1The SGI Free Software License B, although its name says“free”, is not a free software License. It has threemajor problems. 1. It restricts its patent license to unmodifiedversions of the software. 2. It terminates if your use of thesoftware infringes copyrights or patents which are not SGI's. This isproblematic because it gives SGI grounds to sue you even when you havedone nothing to them. 3. The license requires you to inform SGIof legal problems with the software. This violates your privacyrights, and can conflict with professional confidentialityrequirements, such as attorney-client privilege. Squeak licenseAs applied to software, this is not a free software license becauseit requires all users in whatever country to obey US export controllaws. As applied to fonts, it also does not permit modification.In addition, it has a requirement for users to indemnify thedeveloper, which is enough to make many users think twice about using itat all. Sun Community Source LicenseThis is not a free software license; it lacks essential freedoms suchas publication of modified versions. Please don't use this license, andwe urge you to avoid any software that has been released underit.Sun Solaris Source Code (Foundation Release) License, Version 1.1This is not a free software license. The license prohibitsredistribution, prohibits commercial use of the software, and can berevoked. University of Utah Public LicenseThe University of Utah Public License is a non-free license becauseit does not allow commercial redistribution. It also purports torestrict commercially running the software and even commercially givingconsultation about it. Those restrictions are probably not legallyenforceable 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 dangeroustrend for universities to restrict knowledge rather thancontributing it to the public.If a university tries to impose a license like this on the softwareyou are writing, don't give up hope. With persistenceand firmness, and some forethought, it is possible to prevail overmoney-grabbing university administrators.The earlier you raise the issue, the better.YaST LicenseThis is not a free software license. The license prohibitsdistribution for a fee, and that makes it impossible for the software tobe included in the many CD-ROM free software collections that are soldby companies and by organizations such as the FSF.There may be another problem in section 2a, but a word seems to bemissing there, so it is hard to be sure what meaning is reallyintended.(The YaST software itself no longer uses this non-free YaST license;happily, it is now free software, released under the GNU GPL.)Licenses For DocumentationFree Documentation LicensesThe following licenses qualify as freedocumentation licenses. GNU Free Documentation LicenseThis is a license intended for use on copylefted free documentation.We plan to adopt it for all GNU manuals. It is also suitable for otherkinds of useful works (such as textbooks and dictionaries, forinstance). Its applicability is not limited to textual works(“books”). Apple's Common Documentation License, Version 1.0This is a Free Documentation license that is incompatible with theGNU FDL. It is incompatible because Section (2c) says “Youadd no other terms or conditions to those of this License”, andthe GNU FDL has additional terms not accounted for in the CommonDocumentation License. FreeBSD Documentation LicenseThis is a permissive non-copyleft free documentation license that iscompatible with the GNU FDL. Open Publication License, Version 1.0This license can be used as a free documentationlicense. It is a copyleft free documentation licenseprovided the copyright holder does not exercise any ofthe “LICENSE OPTIONS” listed in Section VI of the license.But if either of the options is invoked, the license becomesnon-free. In any case, it is incompatible with the GNU FDL.This creates a practical pitfall in using or recommending thislicense: if you recommend “Use the Open Publication License, Version1.0 but don't enable the options”, it would be easy for the secondhalf of that recommendation to get forgotten; someone might use thelicense with the options, making a manual non-free, and yet think heor she is following your advice.Likewise, if you use this license without either of the options tomake your manual free, someone else might decide to imitate you, thenchange his or her mind about the options thinking that that is just adetail; the result would be that his or her manual is non-free.Thus, while manuals published under this license do qualify as freedocumentation if neither license option was used, it is better to use theGNU Free Documentation License and avoid the risk of leading someone elseastray.Please note that this license is not the same as the Open Content License. These two licenses are frequentlyconfused, as the Open Content License is often referred to as the“OPL”. For clarity, it is better not to use theabbreviation “OPL” for either license. It is worth spellingtheir names in full to make sure people understand what you say.Non-Free Documentation LicensesThe following licenses do not qualifyas free documentation licenses: Open Content License, Version 1.0This license does not qualify as free, because there are restrictions oncharging 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 ofabbreviating “Open Content License” as “OPL”leads to confusion between them. For clarity, it is better not to usethe abbreviation “OPL” for either license. It is worthspelling their names in full to make sure people understand what yousay. Open Directory License (aka dmoz.org License)This is not a free documentation license. The primary problems are thatyour right to redistribute any given version is not permanent and that itrequires the user to keep checking back at that site, which is toorestrictive of the user's freedom.Licenses for Works of Practical Use Besides Software and Documentation GNU General Public LicenseThe GNU GPL can be used for general data which isnot software, as long as one can determine what the definition of“source code” refers to in the particular case. As it turnsout, the DSL (see below) also requires that you determine what the“source code” is, using approximately the same definitionthat the GPL uses. GNU Free Documentation LicenseThe GNU FDL is recommended for textbooks and teaching materials forall topics. (“Documentation” simply means textbooks andother teaching materials for using equipment or software.) We alsorecommend the GNU FDL for dictionaries, encyclopedias, and any otherworks that provide information for practical use. Creative Commons Attribution 2.0 license (a.k.a. CC-BY)This is a non-copyleft free license that is good for art andentertainment works, and educational works. Please don't use it forsoftware or documentation, since it is incompatible with the GNU GPLand with the GNU FDL.Creative Commons publishes many licenses whichare very different. Therefore, to say that a work “uses aCreative Commons license” is to leave the principal questionsabout the work's licensing unanswered. When you see such a statementin a work, please ask the author to highlight the substance of thelicense choices. And if someone proposes to “use a CreativeCommons license” for a certain work, it is vital to askimmediately, “Which one?” Creative Commons Attribution-Sharealike 2.0 license (a.k.a. CC-BY-SA)This is a copyleft free license that is good for artistic andentertainment works, and educational works. Please don't use it forsoftware or documentation, since it is incompatible with the GNU GPLand with the GNU FDL.Please be specific about which Creative Commons license is being used. Design Science License (DSL)This is a free and copyleft license meant for general data.Please don't use it for software or documentation, since it isincompatible with the GNU GPL and with the GNU FDL; however, it isfine to use for other kinds of data. Free Art LicenseThis is a free and copyleft license meant for artistic works. Itpermits commercial distribution, but any larger work including thecopylefted work must be free. Please don't use it for software ordocumentation, since it is incompatible with the GNU GPL and with theGNU FDL.Licenses for FontsThe licenses below apply to an instantation of a design in a computerfile, not the artistic design. As far as we know, an implementation ofa design is always copyrightable. The legal status of the artisticdesign is complex, and varies by jurisdiction. GNU General Public LicenseThe GNU GPL can be used for fonts. However, notethat it does not permit embedding the font in a document unless thatdocument is also licensed under the GPL. If you want to allow this, usethe fontexception. See also this explanatoryessay about the GPL Font Exception. Arphic Public LicenseThis is a copyleft free software license, incompatible with theGPL. Its normal use is for fonts, and in that use, theincompatibility does not cause a problem. SIL Open Font License 1.1The Open Font License (including its original release, version 1.0)is a free copyleft license for fonts. Its only unusual requirement isthat fonts be distributed with some computer program, rather than alone.Since a simple Hello World program will satisfy the requirement, it isharmless. Neither we nor SIL recommend the use of this license foranything other than fonts.Licenses for Works of Opinion and JudgmentWorks that express someone's opinion—memoirs, editorials, andso on—serve a fundamentally different purpose than works forpractical use like software and documentation. Because of this, weexpect them to provide recipients with a different set of permissions:the permission to copy and distribute the work verbatim, for bothcommercial and noncommercial purposes.Richard Stallman discusses this frequentlyin his speeches.Because so many licenses meet these criteria, we cannot list themall. If you are looking for one to use yourself, however, there aretwo that we recommend:GNU Verbatim Copying LicenseThis is the license used throughout the GNU and FSF web sites. It is very simple, and especially well-suited to written works.Creative Commons Attribution-NoDerivs 3.0 license (a.k.a. CC-BY-ND)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. Please be specific about which Creative Commons license is being used.More about licenses. back to top Please send FSF & GNU inquiries to gnu@gnu.org. There are also other ways to contact the FSF. Please send broken links and other corrections or suggestions to webmasters@gnu.org. Please see the Translations README for information on coordinating and submitting translations of this article. Copyright © 2008 Free Software Foundation, Inc. Verbatim copying and distribution of this entire article is permitted in any medium without royalty provided this notice is preserved. Updated: $Date: 2008/09/06 16:38:46 $ Translations of this pageCatalà [ca]Česky [cs]English [en]Español [es]Français [fr]Bahasa Indonesia [id]Italiano [it]日本語 [ja]Polski [pl]português do Brasil [pt-br]Русский [ru] |
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