/[www]/www/philosophy/free-sw.html
ViewVC logotype

Diff of /www/philosophy/free-sw.html

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 1.18 by rms, Mon Aug 26 22:02:14 2002 UTC revision 1.183 by gnun, Sat Jun 25 20:55:18 2022 UTC
# Line 1  Line 1 
1  <!DOCTYPE html PUBLIC "-//IETF//DTD HTML 2.0//EN">  <!--#include virtual="/server/header.html" -->
2  <HTML>  <!-- Parent-Version: 1.96 -->
3  <HEAD>  <!-- This page is derived from /server/standards/boilerplate.html -->
4  <TITLE>The Free Software Definition - GNU Project - Free Software Foundation (FSF)</TITLE>  <!--#set var="TAGS" value="essays aboutfs principles" -->
5  <LINK REV="made" HREF="mailto:webmasters@www.gnu.org">  <!--#set var="DISABLE_TOP_ADDENDUM" value="yes" -->
6  </HEAD>  <title>What is Free Software?
7  <BODY BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#1F00FF" ALINK="#FF0000" VLINK="#9900DD">  - GNU Project - Free Software Foundation</title>
8  <H3>The Free Software Definition</H3>  <style type="text/css" media="print,screen"><!--
9    .toc > ul > li { list-style-type: none; font-weight: bold; }
10  <A HREF="/graphics/philosophicalgnu.html"><IMG SRC="/graphics/philosophical-gnu-sm.jpg"  .toc ul { font-weight: normal; }
11     ALT=" [image of a Philosophical Gnu] "  #History ~ p, #History ~ ul { font-size: 1rem; }
12     WIDTH="160" HEIGHT="200"></A>  --></style>
13    <meta http-equiv="Keywords" content="GNU, FSF, Free Software Foundation, Linux, Emacs, GCC, Unix, Free Software, Operating System, GNU Kernel, HURD, GNU HURD, Hurd" />
14  [  <meta http-equiv="Description" content="Since 1983, developing the free Unix style operating system GNU, so that computer users can have the freedom to share and improve the software they use." />
15  <!-- Please keep this list alphabetical -->  <!--#include virtual="/philosophy/po/free-sw.translist" -->
16  <!-- PLEASE UPDATE THE LIST AT THE BOTTOM (OR TOP) OF THE PAGE TOO! -->  <!--#include virtual="/server/banner.html" -->
17  <A HREF="/philosophy/free-sw.hr.html">Croatian</A>  <!--#include virtual="/philosophy/ph-breadcrumb.html" -->
18  | <A HREF="/philosophy/free-sw.cs.html">Czech</A>  <!--GNUN: OUT-OF-DATE NOTICE-->
19  | <A HREF="/philosophy/free-sw.da.html">Danish</A>  <!--#include virtual="/server/top-addendum.html" -->
20  | <A HREF="/philosophy/free-sw.nl.html">Dutch</A>  <div class="article reduced-width">
21  | <A HREF="/philosophy/free-sw.html">English</A>  <h2>What is Free Software?</h2>
22  | <A HREF="/philosophy/free-sw.fr.html">French</A>  <div class="thin"></div>
23  | <A HREF="/philosophy/free-sw.gl.html">Galician</A>  
24  | <A HREF="/philosophy/free-sw.de.html">German</A>  <div class="important">
25  | <A HREF="/philosophy/free-sw.hu.html">Hungarian</A>  <p>
26  | <A HREF="/philosophy/free-sw.id.html">Indonesian</A>  &ldquo;Free software&rdquo; means software that respects users'
27  | <A HREF="/philosophy/free-sw.it.html">Italian</A>  freedom and community.  Roughly, it means that <b>the users have the
28  | <A HREF="/philosophy/free-sw.ja.html">Japanese</A>  freedom to run, copy, distribute, study, change and improve the
29  | <A HREF="/philosophy/free-sw.ko.html">Korean</A>  software</b>.  Thus, &ldquo;free software&rdquo; is a matter of
30  | <A HREF="/philosophy/free-sw.no.html">Norwegian</A>  liberty, not price.  To understand the concept, you should think of
31  | <A HREF="/philosophy/free-sw.pl.html">Polish</A>  &ldquo;free&rdquo; as in &ldquo;free speech,&rdquo; not as in
32  | <A HREF="/philosophy/free-sw.pt.html">Portuguese</A>  &ldquo;free beer.&rdquo;  We sometimes call it &ldquo;libre
33  | <A HREF="/philosophy/free-sw.ru.html">Russian</A>  software,&rdquo; borrowing the French or Spanish word for
34  | <A HREF="/philosophy/free-sw.sl.html">Slovenian</A>  &ldquo;free&rdquo; as in freedom, to show we do not mean the software
35  | <A HREF="/philosophy/free-sw.es.html">Spanish</A>  is gratis.
36  | <A HREF="/philosophy/free-sw.tr.html">Turkish</A>  </p>
37  <!-- Please keep this list alphabetical -->  
38  <!-- PLEASE UPDATE THE LIST AT THE BOTTOM (OR TOP) OF THE PAGE TOO! -->  <p>
39  ]  You may have paid money to get copies of a free program, or you may
40  <P>  have obtained copies at no charge.  But regardless of how you got your
41    copies, you always have the freedom to copy and change the software,
42  We maintain this free software definition to show clearly what must be  even to <a href="/philosophy/selling.html">sell copies</a>.
43  true about a particular software program for it to be considered  </p>
44  free software.  </div>
45    
46  <P>  <p>
47    We campaign for these freedoms because everyone deserves them.  With
48  ``Free software'' is a matter of liberty, not price.  To understand the  these freedoms, the users (both individually and collectively) control
49  concept, you should think of ``free'' as in ``free speech,'' not as in  the program and what it does for them.  When users don't control the
50  ``free beer.''  program, we call it a &ldquo;nonfree&rdquo; or
51  <P>  &ldquo;proprietary&rdquo; program.  The nonfree program controls the
52  Free software is a matter of the users' freedom to run, copy,  users, and the developer controls the program; this makes the
53  distribute, study, change and improve the software.  More precisely,  program <a href="/philosophy/free-software-even-more-important.html">
54  it refers to four kinds of freedom, for the users of the software:  an instrument of unjust power</a>.
55  <P>  </p>
56    
57  <UL>  <p>
58    <LI>The freedom to run the program, for any purpose (freedom 0).  &ldquo;Open source&rdquo; is something different: it has a very
59    <LI>The freedom to study how the program works, and adapt it to your needs  different philosophy based on different values.  Its practical
60        (freedom 1).   Access to the source code is a precondition for this.  definition is different too, but nearly all open source programs are
61    <LI>The freedom to redistribute copies so you can help your neighbor  in fact free.  We explain the
62    difference in <a href="/philosophy/open-source-misses-the-point.html">
63    Why &ldquo;Open Source&rdquo; misses the point of Free Software</a>.
64    </p>
65    
66    <div class="toc">
67    <hr class="no-display" />
68    <h3 class="no-display">Table of contents</h3>
69    <ul>
70     <li><a href="#fs-definition">The Free Software Definition</a>
71      <ul>
72       <li><a href="#four-freedoms">The four essential freedoms</a></li>
73       <li><a href="#selling">Free software <em>can</em> be commercial</a></li>
74      </ul>
75     </li>
76     <li><a href="#clarifying">Clarifying the Boundary Between Free and Nonfree</a>
77      <ul>
78       <li><a href="#run-the-program">The freedom to run the program as you
79         wish</a></li>
80       <li><a href="#make-changes">The freedom to study the source code and make
81         changes</a></li>
82       <li><a href="#redistribute">The freedom to redistribute if you wish:
83         basic requirements</a></li>
84       <li><a href="#copyleft">Copyleft</a></li>
85       <li><a href="#packaging">Rules about packaging and distribution
86         details</a></li>
87       <li><a href="#exportcontrol">Export regulations</a></li>
88       <li><a href="#legal-details">Legal considerations</a></li>
89       <li><a href="#contracts">Contract-based licenses</a></li>
90      </ul>
91     </li>
92     <li><a href="#in-practice">The Free Software Definition in Practice</a>
93      <ul>
94       <li><a href="#interpretation">How we interpret these criteria</a></li>
95       <li><a href="#get-help">Get help with free licenses</a></li>
96       <li><a href="#terminology">Use the right words when talking about free
97         software</a></li>
98      </ul>
99     </li>
100     <li><a href="#beyond-software">Beyond Software</a></li>
101     <li><a href="#History">History</a></li>
102    </ul>
103    </div>
104    
105    <div class="edu-note" id="fsf-licensing" role="complementary">
106    <p style="font-size:80%">
107    Have a question about free software licensing not answered here?
108    See our other <a href="http://www.fsf.org/licensing">licensing resources</a>,
109    and if necessary contact the FSF Compliance Lab
110    at <a href="mailto:licensing@fsf.org">licensing@fsf.org</a>.</p>
111    <hr class="no-display" />
112    </div>
113    
114    
115    <h3 id="fs-definition">The Free Software Definition</h3>
116    
117    <p>
118    The free software definition presents the criteria for whether a
119    particular software program qualifies as free software.  From time to
120    time we revise this definition, to clarify it or to resolve questions
121    about subtle issues.  See the <a href="#History">History section</a>
122    below for a list of changes that affect the definition of free
123    software.
124    </p>
125    
126    <h4 id="four-freedoms">The four essential freedoms</h4>
127    <p>
128    A program is free software if the program's users have the
129    four essential freedoms: <a href="#f1">[1]</a>
130    </p>
131    
132    <ul class="important">
133      <li>The freedom to run the program as you wish,
134          for any purpose (freedom 0).</li>
135      <li>The freedom to study how the program works, and change it so it
136          does your computing as you wish (freedom 1). Access to the source
137          code is a precondition for this.
138      </li>
139      <li>The freedom to redistribute copies so you can help others
140        (freedom 2).        (freedom 2).
141    <LI>The freedom to improve the program, and release your improvements    </li>
142       to the public, so that the whole community benefits.    <li>The freedom to distribute copies of your modified versions
143        (freedom 3).   Access to the source code is a precondition for this.        to others (freedom 3).  By doing this you can give the whole
144  </UL>        community a chance to benefit from your changes.
145          Access to the source code is a precondition for this.
146  <P>    </li>
147  A program is free software if users have all of these freedoms.  </ul>
148  Thus, you should be free to redistribute copies, either with or  
149  without modifications, either gratis or charging a fee for  <p>
150  distribution, to <A HREF="#exportcontrol">anyone anywhere</A>.  Being  A program is free software if it gives users adequately all of these
151  free to do these things means (among other things) that you do not  freedoms.  Otherwise, it is nonfree.  While we can distinguish various
152  have to ask or pay for permission.  nonfree distribution schemes in terms of how far they fall short of
153    being free, we consider them all equally unethical.</p>
154    
155    <p>In any given scenario, these freedoms must apply to whatever code
156    we plan to make use of, or lead others to make use of.  For instance,
157    consider a program A which automatically launches a program B to
158    handle some cases.  If we plan to distribute A as it stands, that
159    implies users will need B, so we need to judge whether both A and B
160    are free.  However, if we plan to modify A so that it doesn't use B,
161    only A needs to be free; B is not pertinent to that plan.</p>
162    
163    
164    <h4 id="selling">Free software <em>can</em> be commercial</h4>
165    
166    <p>
167    &ldquo;Free software&rdquo; does not mean &ldquo;noncommercial.&rdquo;
168    On the contrary, a free program must be available for commercial use,
169    commercial development, and commercial distribution.  This policy is
170    of fundamental importance&mdash;without this, free software could not
171    achieve its aims.
172    </p>
173    
174    <p>
175    We want to invite everyone to use the GNU system, including businesses
176    and their workers.  That requires allowing commercial use.  We hope
177    that free replacement programs will supplant comparable proprietary
178    programs, but they can't do that if businesses are forbidden to use
179    them.  We want commercial products that contain software to include
180    the GNU system, and that would constitute commercial distribution for
181    a price.  Commercial development of free software is no longer
182    unusual; such free commercial software is very important.  Paid,
183    professional support for free software fills an important need.
184    </p>
185    
186    <p>
187    Thus, to exclude commercial use, commercial development or commercial
188    distribution would hobble the free software community and obstruct its
189    path to success.  We must conclude that a program licensed with such
190    restrictions does not qualify as free software.
191    </p>
192    
193    <p>
194    A free program must offer the four freedoms to any would-be user that
195    obtains a copy of the software, who has complied thus far with the
196    conditions of the free license covering the software in any previous
197    distribution of it.  Putting some of the freedoms off limits to some
198    users, or requiring that users pay, in money or in kind, to exercise
199    them, is tantamount to not granting the freedoms in question, and thus
200    renders the program nonfree.
201    </p>
202    
203    
204    <h3 id="clarifying">Clarifying the Boundary Between Free and Nonfree</h3>
205    
206    <p>In the rest of this article we explain more precisely how far the
207    various freedoms need to extend, on various issues, in order for a
208    program to be free.</p>
209    
210    <h4 id="run-the-program">The freedom to run the program as you wish</h4>
211    
212    <p>
213    The freedom to run the program means the freedom for any kind of person
214    or organization to use it on any kind of computer system, for any kind of
215    overall job and purpose, without being required to communicate about it
216    with the developer or any other specific entity.  In this freedom, it is
217    the <em>user's</em> purpose that matters, not the <em>developer's</em>
218    purpose; you as a user are free to run the program for your purposes,
219    and if you distribute it to someone else, she is then free to run it
220    for her purposes, but you are not entitled to impose your purposes on her.
221    </p>
222    
223    <p>
224    The freedom to run the program as you wish means that you are not
225    forbidden or stopped from making it run.  This has nothing to do with what
226    functionality the program has, whether it is technically capable of
227    functioning in any given environment, or whether it is useful for any
228    particular computing activity.</p>
229    
230    <p>For example, if the code arbitrarily rejects certain meaningful
231    inputs&mdash;or even fails unconditionally&mdash;that may make the
232    program less useful, perhaps even totally useless, but it does not
233    deny users the freedom to run the program, so it does not conflict
234    with freedom 0.  If the program is free, the users can overcome the
235    loss of usefulness, because freedoms 1 and 3 permit users and
236    communities to make and distribute modified versions without the
237    arbitrary nuisance code.</p>
238    
239    <p>&ldquo;As you wish&rdquo; includes, optionally, &ldquo;not at
240    all&rdquo; if that is what you wish.  So there is no need for a
241    separate &ldquo;freedom not to run a program.&rdquo;</p>
242    
243    <h4 id="make-changes">The freedom to study the source code and make changes</h4>
244    
245    <p>
246    In order for freedoms 1 and 3 (the freedom to make changes and the
247    freedom to publish the changed versions) to be meaningful, you need to have
248    access to the source code of the program.  Therefore, accessibility of
249    source code is a necessary condition for free software.  Obfuscated
250    &ldquo;source code&rdquo; is not real source code and does not count
251    as source code.
252    </p>
253    
254    <p>
255    Source code is defined as the preferred form of the program for making
256    changes in.  Thus, whatever form a developer changes to develop
257    the program is the source code of that developer's version.
258    </p>
259    
260    <p>
261    Freedom 1 includes the freedom to use your changed version in place of
262    the original.  If the program is delivered in a product designed to
263    run someone else's modified versions but refuse to run yours&mdash;a
264    practice known as &ldquo;tivoization&rdquo; or &ldquo;lockdown,&rdquo;
265    or (in its practitioners' perverse terminology) as &ldquo;secure
266    boot&rdquo;&mdash;freedom 1 becomes an empty pretense rather than a
267    practical reality.  These binaries are not free
268    software even if the source code they are compiled from is free.
269    </p>
270    
271    <p>
272    One important way to modify a program is by merging in available free
273    subroutines and modules.  If the program's license says that you
274    cannot merge in a suitably licensed existing module&mdash;for instance, if it
275    requires you to be the copyright holder of any code you add&mdash;then the
276    license is too restrictive to qualify as free.
277    </p>
278    
279    <p>
280    Whether a change constitutes an improvement is a subjective matter.
281    If your right to modify a program is limited, in substance, to changes that
282    someone else considers an improvement, that program is not free.
283    </p>
284    
285    <p>
286    One special case of freedom 1 is to delete the program's code so it
287    returns after doing nothing, or make it invoke some other program.
288    Thus, freedom 1 includes the &ldquo;freedom to delete the program.&rdquo;
289    </p>
290    
291    <h4 id="redistribute">The freedom to redistribute if you wish: basic
292    requirements</h4>
293    
294    <p>Freedom to distribute (freedoms 2 and 3) means you are free to
295    redistribute copies, either with or without modifications, either
296    gratis or charging a fee for distribution, to
297    <a href="#exportcontrol">anyone anywhere</a>.  Being free to do these
298    things means (among other things) that you do not have to ask or pay
299    for permission to do so.
300    </p>
301    
302  <P>  <p>
303  You should also have the freedom to make modifications and use them  You should also have the freedom to make modifications and use them
304  privately in your own work or play, without even mentioning that they  privately in your own work or play, without even mentioning that they
305  exist.  If you do publish your changes, you should not be required to  exist.  If you do publish your changes, you should not be required to
306  notify anyone in particular, or in any particular way.  notify anyone in particular, or in any particular way.
307    </p>
308    
309  <P>  <p>
310  The freedom to use a program means the freedom for any kind of person  Freedom 3 includes the freedom to release your modified versions
311  or organization to use it on any kind of computer system, for any kind  as free software.  A free license may also permit other ways of
312  of overall job, and without being required to communicate subsequently  releasing them; in other words, it does not have to be
313  with the developer or any other specific entity.  a <a href="/licenses/copyleft.html">copyleft</a> license.  However, a
314    license that requires modified versions to be nonfree does not qualify
315    as a free license.
316    </p>
317    
318  <P>  <p>
319  The freedom to redistribute copies must include binary or executable  The freedom to redistribute copies must include binary or executable
320  forms of the program, as well as source code, for both modified and  forms of the program, as well as source code, for both modified and
321  unmodified versions.  (Distributing programs in runnable form is  unmodified versions.  (Distributing programs in runnable form is necessary
322  necessary for conveniently installable free operating systems.)  It is  for conveniently installable free operating systems.)  It is OK if there
323  ok if there is no way to produce a binary or executable form for a  is no way to produce a binary or executable form for a certain program
324  certain program (since some languages don't support that feature), but  (since some languages don't support that feature), but you must have the
325  you must have the freedom to redistribute such forms should you find  freedom to redistribute such forms should you find or develop a way to
326  or develop a way to make them.  make them.
327    </p>
328  <P>  
329  In order for the freedoms to make changes, and to publish improved  <h4 id="copyleft">Copyleft</h4>
 versions, to be meaningful, you must have access to the source code of  
 the program.  Therefore, accessibility of source code is a necessary  
 condition for free software.  
   
 <P>  
 In order for these freedoms to be real, they must be irrevocable as  
 long as you do nothing wrong; if the developer of the software has the  
 power to revoke the license, without your doing anything to give  
 cause, the software is not free.  
330    
331  <P>  <p>
332  However, certain kinds of rules about the manner of distributing free  Certain kinds of rules about the manner of distributing free
333  software are acceptable, when they don't conflict with the central  software are acceptable, when they don't conflict with the central
334  freedoms.  For example, copyleft (very simply stated) is the rule that  freedoms.  For example, <a href="/licenses/copyleft.html">copyleft</a>
335  when redistributing the program, you cannot add restrictions to deny  (very simply stated) is the rule that when redistributing the program,
336  other people the central freedoms.  This rule does not conflict with  you cannot add restrictions to deny other people the central freedoms.
337  the central freedoms; rather it protects them.  This rule does not conflict with the central freedoms; rather it
338    protects them.
339  <P>  </p>
340  Thus, you may have paid money to get copies of free software, or you  
341  may have obtained copies at no charge.  But regardless of how you got  <p>
342  your copies, you always have the freedom to copy and change the  In the GNU project, we use copyleft to protect the four freedoms
343  software, even to <A HREF="/philosophy/selling.html">sell copies</A>.  legally for everyone.  We believe there are important reasons why
344  <P>  <a href="/philosophy/pragmatic.html">it is better to use
345    copyleft</a>.  However,
346  ``Free software'' does not mean ``non-commercial''.  A free program  <a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">
347  must be available for commercial use, commercial development, and  noncopylefted free software</a> is ethical
348  commercial distribution.  Commercial development of free software is  too.  See <a href="/philosophy/categories.html">Categories of Free
349  no longer unusual; such free commercial software is very important.  Software</a> for a description of how &ldquo;free software,&rdquo;
350    &ldquo;copylefted software&rdquo; and other categories of software
351  <P>  relate to each other.
352  Rules about how to package a modified version are acceptable, if they  </p>
353  don't effectively block your freedom to release modified versions.  
354  Rules that ``if you make the program available in this way, you must  <h4 id="packaging">Rules about packaging and distribution details</h4>
355  make it available in that way also'' can be acceptable too, on the  
356  same condition.  (Note that such a rule still leaves you the choice of  <p>
357  whether to publish the program or not.)  It is also acceptable for the  Rules about how to package a modified version are acceptable,
358  license to require that, if you have distributed a modified version  if they don't substantively limit your freedom to release modified
359  and a previous developer asks for a copy of it, you must send one.  versions, or your freedom to make and use modified versions privately.
360    Thus, it is acceptable for the license to require that you change the
361  <P>  name of the modified version, remove a logo, or identify your
362  In the GNU project, we use <A HREF="/copyleft/copyleft.html">  modifications as yours.  As long as these requirements are not so
363  ``copyleft''</A> to protect these freedoms legally for everyone.  But  burdensome that they effectively hamper you from releasing your
364  <A HREF="/philosophy/categories.html#Non-CopyleftedFreeSoftware">  changes, they are acceptable; you're already making other changes to
365  non-copylefted free software</A> also exists.  We believe there are  the program, so you won't have trouble making a few more.
366  important reasons why <A HREF="/philosophy/pragmatic.html"> it is  </p>
367  better to use copyleft</A>, but if your program is non-copylefted free  
368  software, we can still use it.  <p>
369    Rules that &ldquo;if you make your version available in this way, you
370  <P>  must make it available in that way also&rdquo; can be acceptable too,
371  See <A HREF="/philosophy/categories.html">Categories of Free Software  on the same condition.  An example of such an acceptable rule is one
372         (18k characters)</A>  saying that if you have distributed a
373  for a description of how ``free software,'' ``copylefted software'' and  modified version and a previous developer asks for a copy of it, you
374  other categories of software relate to each other.  must send one.  (Note that such a rule still leaves you the choice of
375    whether to distribute your version at all.)  Rules that require release
376  <P>  of source code to the users for versions that you put into public use
377  Sometimes government <A NAME="exportcontrol">export control  are also acceptable.
378  regulations</A> and trade sanctions can constrain your freedom to  </p>
379  distribute copies of programs internationally.  Software developers do  
380  not have the power to eliminate or override these restrictions, but  <p>
381  what they can and must do is refuse to impose them as conditions of  A special issue arises when a license requires changing the name by
382  use of the program.  In this way, the restrictions will not affect  which the program will be invoked from other programs.  That
383  activities and people outside the jurisdictions of these governments.  effectively hampers you from releasing your changed version so that it
384    can replace the original when invoked by those other programs.  This
385  <P>  sort of requirement is acceptable only if there's a suitable aliasing
386  When talking about free software, it is best to avoid using terms like  facility that allows you to specify the original program's name as an
387  ``give away'' or ``for free'', because those terms imply that the  alias for the modified version.</p>
388  issue is about price, not freedom.  Some common terms such as  
389  ``piracy'' embody opinions we hope you won't endorse.  See <A  <h4 id="exportcontrol">Export regulations</h4>
390  HREF="/philosophy/words-to-avoid.html">Confusing Words and Phrases  
391  that are Worth Avoiding</A> for a discussion of these terms.  <p>
392  We also have a list of <A HREF="/philosophy/fs-translations.html">translations  Sometimes government export control regulations
393  of "free software"</A> into various languages.  and trade sanctions can constrain your freedom to distribute copies of
394    programs internationally.  Software developers do not have the power to
395  <P>  eliminate or override these restrictions, but what they can and must do
396    is refuse to impose them as conditions of use of the program.  In this
397  Finally, note that criteria such as those stated in this free software  way, the restrictions will not affect activities and people outside the
398  definition require careful thought for their interpretation.  To  jurisdictions of these governments.  Thus, free software licenses
399  decide whether a specific software license qualifies as a free  must not require obedience to any nontrivial export regulations as a
400  software license, we judge it based on these criteria to determine  condition of exercising any of the essential freedoms.
401  whether it fits their spirit as well as the precise words.  If a  </p>
402  license includes unconscionable restrictions, we reject it, even if we  
403  did not anticipate the issue in these criteria.  Sometimes a license  <p>
404  requirement raises an issue that calls for extensive thought,  Merely mentioning the existence of export regulations, without making
405  including discussions with a lawyer, before we can decide if the  them a condition of the license itself, is acceptable since it does
406  requirement is acceptable.  When we reach a conclusion about a new  not restrict users.  If an export regulation is actually trivial for
407  issue, we often update these criteria to make it easier to see why  free software, then requiring it as a condition is not an actual
408  certain licenses do or don't qualify.  problem; however, it is a potential problem, since a later change in
409    export law could make the requirement nontrivial and thus render the
410  <P>  software nonfree.
411    </p>
412  If you are interested in whether a specific license qualifies as a  
413  free software license, see our <A  <h4 id="legal-details">Legal considerations</h4>
414  HREF="/licenses/license-list.html">list of licenses</A>.  If the  
415  license you are concerned with is not listed there, you can ask us  <p>
416  about it by sending us email at <A  In order for these freedoms to be real, they must be permanent and
417  HREF="mailto:licensing@gnu.org">&lt;licensing@gnu.org&gt;</A>.  irrevocable as long as you do nothing wrong; if the developer of the
418    software has the power to revoke the license, or retroactively add
419  <HR>  restrictions to its terms, without your doing anything wrong to give
420    cause, the software is not free.
421  <H4><A HREF="/philosophy/philosophy.html">Other Texts to Read</A></H4>  </p>
422    
423  <P>  <p>
424  Another group has started using the term "open source" to mean  A free license may not require compliance with the license of a
425  something close (but not identical) to "free software".  We prefer the  nonfree program.  Thus, for instance, if a license requires you to
426  term "free software" because, once you have heard it refers to freedom  comply with the licenses of &ldquo;all the programs you use,&rdquo; in
427  rather than price, <A HREF="free-software-for-freedom.html">it calls  the case of a user that runs nonfree programs this would require
428  to mind freedom</A>.  compliance with the licenses of those nonfree programs; that makes the
429    license nonfree.
430  <HR>  </p>
431  [  
432  <!-- Please keep this list alphabetical -->  <p>
433  <!-- PLEASE UPDATE THE LIST AT THE BOTTOM (OR TOP) OF THE PAGE TOO! -->  It is acceptable for a free license to specify which jurisdiction's
434  <A HREF="/philosophy/free-sw.hr.html">Croatian</A>  law applies, or where litigation must be done, or both.
435  | <A HREF="/philosophy/free-sw.cs.html">Czech</A>  </p>
436  | <A HREF="/philosophy/free-sw.da.html">Danish</A>  
437  | <A HREF="/philosophy/free-sw.nl.html">Dutch</A>  <h4 id="contracts">Contract-based licenses</h4>
438  | <A HREF="/philosophy/free-sw.html">English</A>  
439  | <A HREF="/philosophy/free-sw.fr.html">French</A>  <p>
440  | <A HREF="/philosophy/free-sw.gl.html">Galician</A>  Most free software licenses are based on copyright, and there are limits
441  | <A HREF="/philosophy/free-sw.de.html">German</A>  on what kinds of requirements can be imposed through copyright.  If a
442  | <A HREF="/philosophy/free-sw.hu.html">Hungarian</A>  copyright-based license respects freedom in the ways described above, it
443  | <A HREF="/philosophy/free-sw.id.html">Indonesian</A>  is unlikely to have some other sort of problem that we never anticipated
444  | <A HREF="/philosophy/free-sw.it.html">Italian</A>  (though this does happen occasionally).  However, some free software
445  | <A HREF="/philosophy/free-sw.ja.html">Japanese</A>  licenses are based on contracts, and contracts can impose a much larger
446  | <A HREF="/philosophy/free-sw.ko.html">Korean</A>  range of possible restrictions.  That means there are many possible ways
447  | <A HREF="/philosophy/free-sw.no.html">Norwegian</A>  such a license could be unacceptably restrictive and nonfree.
448  | <A HREF="/philosophy/free-sw.pl.html">Polish</A>  </p>
449  | <A HREF="/philosophy/free-sw.pt.html">Portuguese</A>  
450  | <A HREF="/philosophy/free-sw.ru.html">Russian</A>  <p>
451  | <A HREF="/philosophy/free-sw.sl.html">Slovenian</A>        We can't possibly list all the ways that might happen.  If a
452  | <A HREF="/philosophy/free-sw.es.html">Spanish</A>  contract-based license restricts the user in an unusual way that
453  | <A HREF="/philosophy/free-sw.tr.html">Turkish</A>  copyright-based licenses cannot, and which isn't mentioned here as
454  <!-- Please keep this list alphabetical -->  legitimate, we will have to think about it, and we will probably conclude
455  <!-- PLEASE UPDATE THE LIST AT THE BOTTOM (OR TOP) OF THE PAGE TOO! -->  it is nonfree.
456  ]  </p>
457  <P>  
458  Return to <A HREF="/home.html">GNU's home page</A>.  <h3 id="in-practice">The Free Software Definition in Practice</h3>
459  <P>  
460    <h4 id="interpretation">How we interpret these criteria</h4>
461  Please send FSF &amp; GNU inquiries &amp; questions to  
462    <p>
463  <A HREF="mailto:gnu@gnu.org"><EM>gnu@gnu.org</EM></A>.  Note that criteria such as those stated in this free software
464  There are also <A HREF="/home.html#ContactInfo">other ways to  definition require careful thought for their interpretation.  To decide
465  contact</A> the FSF.  whether a specific software license qualifies as a free software license,
466  <P>  we judge it based on these criteria to determine whether it fits their
467    spirit as well as the precise words.  If a license includes unconscionable
468  Please send comments on these web pages to  restrictions, we reject it, even if we did not anticipate the issue
469    in these criteria.  Sometimes a license requirement raises an issue
470  <A HREF="mailto:webmasters@gnu.org"><EM>webmasters@gnu.org</EM></A>,  that calls for extensive thought, including discussions with a lawyer,
471  send other questions to  before we can decide if the requirement is acceptable.  When we reach
472  <A HREF="mailto:gnu@gnu.org"><EM>gnu@gnu.org</EM></A>.  a conclusion about a new issue, we often update these criteria to make
473  <P>  it easier to see why certain licenses do or don't qualify.
474  Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.,  </p>
475  59 Temple Place - Suite 330, Boston, MA  02111,  USA  
476  <P>  <h4 id="get-help">Get help with free licenses</h4>
477  Verbatim copying and distribution of this entire article is  
478  permitted in any medium, provided this notice is preserved.  <p>
479  <P>  If you are interested in whether a specific license qualifies as a free
480  Updated:  software license, see our <a href="/licenses/license-list.html">list
481    of licenses</a>.  If the license you are concerned with is not
482    listed there, you can ask us about it by sending us email at
483    <a href="mailto:licensing@gnu.org">&lt;licensing@gnu.org&gt;</a>.
484    </p>
485    
486    <p>
487    If you are contemplating writing a new license, please contact the
488    Free Software Foundation first by writing to that address. The
489    proliferation of different free software licenses means increased work
490    for users in understanding the licenses; we may be able to help you
491    find an existing free software license that meets your needs.
492    </p>
493    
494    <p>
495    If that isn't possible, if you really need a new license, with our
496    help you can ensure that the license really is a free software license
497    and avoid various practical problems.
498    </p>
499    
500    <h4 id="terminology">Use the right words when talking about free software</h4>
501    
502    <p>
503    When talking about free software, it is best to avoid using terms
504    like &ldquo;give away&rdquo; or &ldquo;for free,&rdquo; because those terms imply that
505    the issue is about price, not freedom.  Some common terms such
506    as &ldquo;piracy&rdquo; embody opinions we hope you won't endorse.  See
507    <a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases that
508    are Worth Avoiding</a> for a discussion of these terms.  We also have
509    a list of proper <a href="/philosophy/fs-translations.html">translations of
510    &ldquo;free software&rdquo;</a> into various languages.
511    </p>
512    
513    <p id="open-source">
514    Another group uses the term &ldquo;open source&rdquo; to mean
515    something close (but not identical) to &ldquo;free software.&rdquo;  We
516    prefer the term &ldquo;free software&rdquo; because, once you have heard that
517    it refers to freedom rather than price, it calls to mind freedom.  The
518    word &ldquo;open&rdquo; never refers to freedom.
519    </p>
520    
521    <h3 id="beyond-software">Beyond Software</h3>
522    
523    <p>
524    <a href="/philosophy/free-doc.html">Software manuals must be free</a>,
525    for the same reasons that software must be free, and because the
526    manuals are in effect part of the software.
527    </p>
528    
529    <p>
530    The same arguments also make sense for other kinds of works of
531    practical use&mdash;that is to say, works that embody useful knowledge,
532    such as educational works and reference
533    works.  <a href="https://wikipedia.org">Wikipedia</a> is the best-known
534    example.
535    </p>
536    
537    <p>
538    Any kind of work <em>can</em> be free, and the definition of free software
539    has been extended to a definition of <a href="http://freedomdefined.org/">
540    free cultural works</a> applicable to any kind of works.
541    </p>
542    
543    <h3 id="History">History</h3>
544    
545    <p>From time to time we revise this Free Software Definition.  Here is
546    the list of substantive changes, along with links to show exactly what
547    was changed.</p>
548    
549    <ul>
550    
551    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.168&amp;r2=1.169">Version
552    1.169</a>: Explain more clearly why the four freedoms must apply
553    to commercial activity.  Explain why the four freedoms imply the
554    freedom not to run the program and the freedom to delete it, so there
555    is no need to state those as separate requirements.</li>
556    
557    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.164&amp;r2=1.165">Version
558    1.165</a>: Clarify that arbitrary annoyances in the code do not
559    negate freedom 0, and that freedoms 1 and 3 enable users to remove them.</li>
560    
561    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.152&amp;r2=1.153">Version
562    1.153</a>: Clarify that freedom to run the program means nothing stops
563    you from making it run.</li>
564    
565    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.140&amp;r2=1.141">Version
566    1.141</a>: Clarify which code needs to be free.</li>
567    
568    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.134&amp;r2=1.135">Version
569    1.135</a>: Say each time that freedom 0 is the freedom to run the program
570    as you wish.</li>
571    
572    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.133&amp;r2=1.134">Version
573    1.134</a>: Freedom 0 is not a matter of the program's functionality.</li>
574    
575    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.130&amp;r2=1.131">Version
576    1.131</a>: A free license may not require compliance with a nonfree license
577    of another program.</li>
578    
579    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.128&amp;r2=1.129">Version
580    1.129</a>: State explicitly that choice of law and choice of forum
581    specifications are allowed.  (This was always our policy.)</li>
582    
583    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.121&amp;r2=1.122">Version
584    1.122</a>: An export control requirement is a real problem if the
585    requirement is nontrivial; otherwise it is only a potential problem.</li>
586    
587    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.117&amp;r2=1.118">Version
588    1.118</a>: Clarification: the issue is limits on your right to modify,
589    not on what modifications you have made.  And modifications are not limited
590    to &ldquo;improvements&rdquo;</li>
591    
592    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.110&amp;r2=1.111">Version
593    1.111</a>: Clarify 1.77 by saying that only
594    retroactive <em>restrictions</em> are unacceptable.  The copyright
595    holders can always grant additional <em>permission</em> for use of the
596    work by releasing the work in another way in parallel.</li>
597    
598    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.104&amp;r2=1.105">Version
599    1.105</a>: Reflect, in the brief statement of freedom 1, the point
600    (already stated in version 1.80) that it includes really using your modified
601    version for your computing.</li>
602    
603    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.91&amp;r2=1.92">Version
604    1.92</a>: Clarify that obfuscated code does not qualify as source code.</li>
605    
606    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.89&amp;r2=1.90">Version
607    1.90</a>: Clarify that freedom 3 means the right to distribute copies
608    of your own modified or improved version, not a right to participate
609    in someone else's development project.</li>
610    
611    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.88&amp;r2=1.89">Version
612    1.89</a>: Freedom 3 includes the right to release modified versions as
613    free software.</li>
614    
615    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.79&amp;r2=1.80">Version
616    1.80</a>: Freedom 1 must be practical, not just theoretical;
617    i.e., no tivoization.</li>
618    
619    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.76&amp;r2=1.77">Version
620    1.77</a>: Clarify that all retroactive changes to the license are
621    unacceptable, even if it's not described as a complete
622    replacement.</li>
623    
624    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.73&amp;r2=1.74">Version
625    1.74</a>: Four clarifications of points not explicit enough, or stated
626    in some places but not reflected everywhere:
627    <ul>
628    <li>&ldquo;Improvements&rdquo; does not mean the license can
629    substantively limit what kinds of modified versions you can release.
630    Freedom 3 includes distributing modified versions, not just changes.</li>
631    <li>The right to merge in existing modules
632    refers to those that are suitably licensed.</li>
633    <li>Explicitly state the conclusion of the point about export controls.</li>
634    <li>Imposing a license change constitutes revoking the old license.</li>
635    </ul>
636    </li>
637    
638    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.56&amp;r2=1.57">Version
639    1.57</a>: Add &ldquo;Beyond Software&rdquo; section.</li>
640    
641    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.45&amp;r2=1.46">Version
642    1.46</a>: Clarify whose purpose is significant in the freedom to run
643    the program for any purpose.</li>
644    
645    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.40&amp;r2=1.41">Version
646    1.41</a>: Clarify wording about contract-based licenses.</li>
647    
648    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.39&amp;r2=1.40">Version
649    1.40</a>: Explain that a free license must allow to you use other
650    available free software to create your modifications.</li>
651    
652    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.38&amp;r2=1.39">Version
653    1.39</a>: Note that it is acceptable for a license to require you to
654    provide source for versions of the software you put into public
655    use.</li>
656    
657    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.30&amp;r2=1.31">Version
658    1.31</a>: Note that it is acceptable for a license to require you to
659    identify yourself as the author of modifications.  Other minor
660    clarifications throughout the text.</li>
661    
662    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.22&amp;r2=1.23">Version
663    1.23</a>: Address potential problems related to contract-based
664    licenses.</li>
665    
666    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.15&amp;r2=1.16">Version
667    1.16</a>: Explain why distribution of binaries is important.</li>
668    
669    <li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.10&amp;r2=1.11">Version
670    1.11</a>: Note that a free license may require you to send a copy of
671    versions you distribute to previous developers on request.</li>
672    
673    </ul>
674    
675    <p>There are gaps in the version numbers shown above because there are
676    other changes in this page that do not affect the definition or its
677    interpretations.  For instance, the list does not include changes in
678    asides, formatting, spelling, punctuation, or other parts of the page.
679    You can review the complete list of changes to the page through
680    the <a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;view=log">cvsweb
681    interface</a>.</p>
682    <div class="column-limit"></div>
683    
684    <h3 class="footnote">Footnote</h3>
685    <ol>
686    <li id="f1">The reason they are numbered 0, 1, 2 and 3 is historical. Around
687    1990 there were three freedoms, numbered 1, 2 and 3. Then we realized that
688    the freedom to run the program needed to be mentioned explicitly.
689    It was clearly more basic than the other three, so it properly should
690    precede them. Rather than renumber the others, we made it freedom&nbsp;0.</li>
691    </ol>
692    </div>
693    
694    </div><!-- for id="content", starts in the include above -->
695    <!--#include virtual="/server/footer.html" -->
696    <div id="footer" role="contentinfo">
697    <div class="unprintable">
698    
699    <p>Please send general FSF &amp; GNU inquiries to
700    <a href="mailto:gnu@gnu.org">&lt;gnu@gnu.org&gt;</a>.
701    There are also <a href="/contact/">other ways to contact</a>
702    the FSF.  Broken links and other corrections or suggestions can be sent
703    to <a href="mailto:webmasters@gnu.org">&lt;webmasters@gnu.org&gt;</a>.</p>
704    
705    <p><!-- TRANSLATORS: Ignore the original text in this paragraph,
706            replace it with the translation of these two:
707    
708            We work hard and do our best to provide accurate, good quality
709            translations.  However, we are not exempt from imperfection.
710            Please send your comments and general suggestions in this regard
711            to <a href="mailto:web-translators@gnu.org">
712            &lt;web-translators@gnu.org&gt;</a>.</p>
713    
714            <p>For information on coordinating and contributing translations of
715            our web pages, see <a
716            href="/server/standards/README.translations.html">Translations
717            README</a>. -->
718    Please see the <a
719    href="/server/standards/README.translations.html">Translations
720    README</a> for information on coordinating and contributing translations
721    of this article.</p>
722    </div>
723    
724    <!-- Regarding copyright, in general, standalone pages (as opposed to
725         files generated as part of manuals) on the GNU web server should
726         be under CC BY-ND 4.0.  Please do NOT change or remove this
727         without talking with the webmasters or licensing team first.
728         Please make sure the copyright date is consistent with the
729         document.  For web pages, it is ok to list just the latest year the
730         document was modified, or published.
731        
732         If you wish to list earlier years, that is ok too.
733         Either "2001, 2002, 2003" or "2001-2003" are ok for specifying
734         years, as long as each year in the range is in fact a copyrightable
735         year, i.e., a year in which the document was published (including
736         being publicly visible on the web or in a revision control system).
737        
738         There is more detail about copyright years in the GNU Maintainers
739         Information document, www.gnu.org/prep/maintain. -->
740    
741    <p>Copyright &copy; 1996-2002, 2004-2019, 2021, 2022
742    Free Software Foundation, Inc.</p>
743    
744    <p>This page is licensed under a <a rel="license"
745    href="http://creativecommons.org/licenses/by-nd/4.0/">Creative
746    Commons Attribution-NoDerivatives 4.0 International License</a>.</p>
747    
748    <!--#include virtual="/server/bottom-notes.html" -->
749    
750    <p class="unprintable">Updated:
751  <!-- timestamp start -->  <!-- timestamp start -->
752  $Date$ $Author$  $Date$
753  <!-- timestamp end -->  <!-- timestamp end -->
754  <HR>  </p>
755  </BODY>  </div>
756  </HTML>  </div><!-- for class="inner", starts in the banner include -->
757    </body>
758    </html>
Legend:
Removed from v.1.18  
changed lines
  Added in v.1.183
savannah-hackers-public@gnu.org
 ViewVC Help
Powered by ViewVC 1.1.26