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3  <HEAD>  <title>What is free software?
4  <TITLE>The Free Software Definition - GNU Project - Free Software Foundation (FSF)</TITLE>  - GNU Project - Free Software Foundation</title>
5  <LINK REV="made" HREF="mailto:webmasters@www.gnu.org">  <style type="text/css" media="print,screen"><!--
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8  <H3>The Free Software Definition</H3>     .note { margin-top: .8em; }
9    }
10  <A HREF="/graphics/philosophicalgnu.html"><IMG SRC="/graphics/philosophical-gnu-sm.jpg"  --></style>
11     ALT=" [image of a Philosophical Gnu] "  <meta http-equiv="Keywords" content="GNU, FSF, Free Software Foundation, Linux, Emacs, GCC, Unix, Free Software, Operating System, GNU Kernel, HURD, GNU HURD, Hurd" />
12     WIDTH="160" HEIGHT="200"></A>  <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." />
13    
14  [  <!--#include virtual="/philosophy/po/free-sw.translist" -->
15  <!-- Please keep this list alphabetical -->  <!--#include virtual="/server/banner.html" -->
16  <!-- PLEASE UPDATE THE LIST AT THE BOTTOM (OR TOP) OF THE PAGE TOO! -->  
17  <A HREF="/philosophy/free-sw.hr.html">Croatian</A>  <h2>What is free software?</h2>
18  | <A HREF="/philosophy/free-sw.cs.html">Czech</A>  
19  | <A HREF="/philosophy/free-sw.da.html">Danish</A>  <div class="article">
20  | <A HREF="/philosophy/free-sw.nl.html">Dutch</A>  <h3>The Free Software Definition</h3>
21  | <A HREF="/philosophy/free-sw.html">English</A>  
22  | <A HREF="/philosophy/free-sw.fr.html">French</A>  <blockquote class="note" id="fsf-licensing"><p style="font-size: 80%">
23  | <A HREF="/philosophy/free-sw.gl.html">Galician</A>  Have a question about free software licensing not answered here?
24  | <A HREF="/philosophy/free-sw.de.html">German</A>  See our other <a href="http://www.fsf.org/licensing">licensing resources</a>,
25  | <A HREF="/philosophy/free-sw.hu.html">Hungarian</A>  and if necessary contact the FSF Compliance Lab
26  | <A HREF="/philosophy/free-sw.id.html">Indonesian</A>  at <a href="mailto:licensing@fsf.org">licensing@fsf.org</a>.</p>
27  | <A HREF="/philosophy/free-sw.it.html">Italian</A>  </blockquote>
28  | <A HREF="/philosophy/free-sw.ja.html">Japanese</A>  
29  | <A HREF="/philosophy/free-sw.ko.html">Korean</A>  <div class="comment">
30  | <A HREF="/philosophy/free-sw.no.html">Norwegian</A>  <p>
31  | <A HREF="/philosophy/free-sw.pl.html">Polish</A>  The free software definition presents the criteria for whether a
32  | <A HREF="/philosophy/free-sw.pt.html">Portuguese</A>  particular software program qualifies as free software.  From time to
33  | <A HREF="/philosophy/free-sw.ro.html">Romanian</A>  time we revise this definition, to clarify it or to resolve questions
34  | <A HREF="/philosophy/free-sw.ru.html">Russian</A>  about subtle issues.  See the <a href="#History">History section</a>
35  | <A HREF="/philosophy/free-sw.sl.html">Slovenian</A>  below for a list of changes that affect the definition of free
36  | <A HREF="/philosophy/free-sw.es.html">Spanish</A>  software.
37  | <A HREF="/philosophy/free-sw.sv.html">Swedish</A>    </p>
38  | <A HREF="/philosophy/free-sw.tr.html">Turkish</A>  
39  <!-- Please keep this list alphabetical -->  <p>
40  <!-- PLEASE UPDATE THE LIST AT THE BOTTOM (OR TOP) OF THE PAGE TOO! -->  &ldquo;Open source&rdquo; is something different: it has a very
41  ]  different philosophy based on different values.  Its practical
42  <P>  definition is different too, but nearly all open source programs are
43    in fact free.  We explain the
44  We maintain this free software definition to show clearly what must be  difference in <a href="/philosophy/open-source-misses-the-point.html">
45  true about a particular software program for it to be considered  Why &ldquo;Open Source&rdquo; misses the point of Free Software</a>.
46  free software.  </p>
47    </div>
48  <P>  
49    <p>
50  ``Free software'' is a matter of liberty, not price.  To understand the  &ldquo;Free software&rdquo; means software that respects users'
51  concept, you should think of ``free'' as in ``free speech,'' not as in  freedom and community.  Roughly, it means that <b>the users have the
52  ``free beer.''  freedom to run, copy, distribute, study, change and improve the
53  <P>  software</b>.  Thus, &ldquo;free software&rdquo; is a matter of
54  Free software is a matter of the users' freedom to run, copy,  liberty, not price.  To understand the concept, you should think of
55  distribute, study, change and improve the software.  More precisely,  &ldquo;free&rdquo; as in &ldquo;free speech,&rdquo; not as in
56  it refers to four kinds of freedom, for the users of the software:  &ldquo;free beer&rdquo;.  We sometimes call it &ldquo;libre
57  <P>  software,&rdquo; borrowing the French or Spanish word for
58    &ldquo;free&rdquo; as in freedom, to show we do not mean the software
59  <UL>  is gratis.
60    <LI>The freedom to run the program, for any purpose (freedom 0).  </p>
61    <LI>The freedom to study how the program works, and adapt it to your needs  
62        (freedom 1).   Access to the source code is a precondition for this.  <p>
63    <LI>The freedom to redistribute copies so you can help your neighbor  We campaign for these freedoms because everyone deserves them.  With
64    these freedoms, the users (both individually and collectively) control
65    the program and what it does for them.  When users don't control the
66    program, we call it a &ldquo;nonfree&rdquo; or
67    &ldquo;proprietary&rdquo; program.  The nonfree program controls the
68    users, and the developer controls the program; this makes the
69    program <a href="/philosophy/free-software-even-more-important.html">
70    an instrument of unjust power</a>.
71    </p>
72    
73    <h4> The four essential freedoms</h4>
74    
75    <p>
76    A program is free software if the program's users have the
77    four essential freedoms: <a href="#f1">[1]</a>
78    </p>
79    
80    <ul class="important">
81      <li>The freedom to run the program as you wish,
82          for any purpose (freedom 0).</li>
83      <li>The freedom to study how the program works, and change it so it
84          does your computing as you wish (freedom 1). Access to the source
85          code is a precondition for this.
86      </li>
87      <li>The freedom to redistribute copies so you can help others
88        (freedom 2).        (freedom 2).
89    <LI>The freedom to improve the program, and release your improvements    </li>
90       to the public, so that the whole community benefits    <li>The freedom to distribute copies of your modified versions
91        (freedom 3).   Access to the source code is a precondition for this.        to others (freedom 3).  By doing this you can give the whole
92  </UL>        community a chance to benefit from your changes.
93          Access to the source code is a precondition for this.
94  <P>    </li>
95  A program is free software if users have all of these freedoms.  </ul>
96  Thus, you should be free to redistribute copies, either with or  
97  without modifications, either gratis or charging a fee for  <p>
98  distribution, to <A HREF="#exportcontrol">anyone anywhere</A>.  Being  A program is free software if it gives users adequately all of these
99  free to do these things means (among other things) that you do not  freedoms.  Otherwise, it is nonfree.  While we can distinguish various
100  have to ask or pay for permission.  nonfree distribution schemes in terms of how far they fall short of
101    being free, we consider them all equally unethical.</p>
102    
103    <p>In any given scenario, these freedoms must apply to whatever code
104    we plan to make use of, or lead others to make use of.  For instance,
105    consider a program A which automatically launches a program B to
106    handle some cases.  If we plan to distribute A as it stands, that
107    implies users will need B, so we need to judge whether both A and B
108    are free.  However, if we plan to modify A so that it doesn't use B,
109    only A needs to be free; B is not pertinent to that plan.</p>
110    
111    <p>
112    &ldquo;Free software&rdquo; does not mean &ldquo;noncommercial&rdquo;.  A free
113    program must be available for commercial use, commercial development,
114    and commercial distribution.  Commercial development of free software
115    is no longer unusual; such free commercial software is very important.
116    You may have paid money to get copies of free software, or you may have
117    obtained copies at no charge.  But regardless of how you got your copies,
118    you always have the freedom to copy and change the software, even to
119    <a href="/philosophy/selling.html">sell copies</a>.
120    </p>
121    
122    <p>
123    A free program must offer the four freedoms to any user that obtains a
124    copy of the software, provided the user has complied thus far with the
125    conditions of the free license covering the software.  Putting some of
126    the freedoms off limits to some users, or requiring that users pay, in
127    money or in kind, to exercise them, is tantamount to not granting the
128    freedoms in question, and thus renders the program nonfree.
129    </p>
130    
131    <h3>Clarifying the line at various points</h3>
132    
133    <p>In the rest of this article we explain more precisely how far the
134    various freedoms need to extend, on various issues, in order for a
135    program to be free.</p>
136    
137    <h4>The freedom to run the program as you wish</h4>
138    
139    <p>
140    The freedom to run the program means the freedom for any kind of person
141    or organization to use it on any kind of computer system, for any kind of
142    overall job and purpose, without being required to communicate about it
143    with the developer or any other specific entity.  In this freedom, it is
144    the <em>user's</em> purpose that matters, not the <em>developer's</em>
145    purpose; you as a user are free to run the program for your purposes,
146    and if you distribute it to someone else, she is then free to run it
147    for her purposes, but you are not entitled to impose your purposes on her.
148    </p>
149    
150    <p>
151    The freedom to run the program as you wish means that you are not
152    forbidden or stopped from making it run.  This has nothing to do with what
153    functionality the program has, whether it is technically capable of
154    functioning in any given environment, or whether it is useful for any
155    particular computing activity.</p>
156    
157    <p>For example, if the code arbitrarily rejects certain meaningful
158    inputs&mdash;or even fails unconditionally&mdash;that may make the
159    program less useful, perhaps even totally useless, but it does not
160    deny users the freedom to run the program, so it does not conflict
161    with freedom 0.  If the program is free, the users can overcome the
162    loss of usefulness, because freedoms 1 and 3 permit users and
163    communities to make and distribute modified versions without the
164    arbitrary nuisance code.</p>
165    
166    <h4>The freedom to study the source code and make changes</h4>
167    
168    <p>
169    In order for freedoms 1 and 3 (the freedom to make changes and the
170    freedom to publish the changed versions) to be meaningful, you need to have
171    access to the source code of the program.  Therefore, accessibility of
172    source code is a necessary condition for free software.  Obfuscated
173    &ldquo;source code&rdquo; is not real source code and does not count
174    as source code.
175    </p>
176    
177    <p>
178    Freedom 1 includes the freedom to use your changed version in place of
179    the original.  If the program is delivered in a product designed to
180    run someone else's modified versions but refuse to run yours &mdash; a
181    practice known as &ldquo;tivoization&rdquo; or &ldquo;lockdown&rdquo;,
182    or (in its practitioners' perverse terminology) as &ldquo;secure
183    boot&rdquo; &mdash; freedom 1 becomes an empty pretense rather than a
184    practical reality.  These binaries are not free
185    software even if the source code they are compiled from is free.
186    </p>
187    
188    <p>
189    One important way to modify a program is by merging in available free
190    subroutines and modules.  If the program's license says that you
191    cannot merge in a suitably licensed existing module &mdash; for instance, if it
192    requires you to be the copyright holder of any code you add &mdash; then the
193    license is too restrictive to qualify as free.
194    </p>
195    
196    <p>
197    Whether a change constitutes an improvement is a subjective matter.
198    If your right to modify a program is limited, in substance, to changes that
199    someone else considers an improvement, that program is not free.
200    </p>
201    
202    <h4>The freedom to redistribute if you wish: basic requirements</h4>
203    
204    <p>Freedom to distribute (freedoms 2 and 3) means you are free to
205    redistribute copies, either with or without modifications, either
206    gratis or charging a fee for distribution, to
207    <a href="#exportcontrol">anyone anywhere</a>.  Being free to do these
208    things means (among other things) that you do not have to ask or pay
209    for permission to do so.
210    </p>
211    
212  <P>  <p>
213  You should also have the freedom to make modifications and use them  You should also have the freedom to make modifications and use them
214  privately in your own work or play, without even mentioning that they  privately in your own work or play, without even mentioning that they
215  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
216  notify anyone in particular, or in any particular way.  notify anyone in particular, or in any particular way.
217    </p>
218    
219  <P>  <p>
220  The freedom to use a program means the freedom for any kind of person  Freedom 3 includes the freedom to release your modified versions
221  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
222  of overall job, and without being required to communicate subsequently  releasing them; in other words, it does not have to be
223  with the developer or any other specific entity.  a <a href="/copyleft/copyleft.html">copyleft</a> license.  However, a
224    license that requires modified versions to be nonfree does not qualify
225    as a free license.
226    </p>
227    
228  <P>  <p>
229  The freedom to redistribute copies must include binary or executable  The freedom to redistribute copies must include binary or executable
230  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
231  unmodified versions.  (Distributing programs in runnable form is  unmodified versions.  (Distributing programs in runnable form is necessary
232  necessary for conveniently installable free operating systems.)  It is  for conveniently installable free operating systems.)  It is OK if there
233  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
234  certain program (since some languages don't support that feature), but  (since some languages don't support that feature), but you must have the
235  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
236  or develop a way to make them.  make them.
237    </p>
238  <P>  
239  In order for the freedoms to make changes, and to publish improved  <h4>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.  
240    
241  <P>  <p>
242  However, certain kinds of rules about the manner of distributing free  Certain kinds of rules about the manner of distributing free
243  software are acceptable, when they don't conflict with the central  software are acceptable, when they don't conflict with the central
244  freedoms.  For example, copyleft (very simply stated) is the rule that  freedoms.  For example, <a href="/copyleft/copyleft.html">copyleft</a>
245  when redistributing the program, you cannot add restrictions to deny  (very simply stated) is the rule that when redistributing the program,
246  other people the central freedoms.  This rule does not conflict with  you cannot add restrictions to deny other people the central freedoms.
247  the central freedoms; rather it protects them.  This rule does not conflict with the central freedoms; rather it
248    protects them.
249  <P>  </p>
250  Thus, you may have paid money to get copies of free software, or you  
251  may have obtained copies at no charge.  But regardless of how you got  <p>
252  your copies, you always have the freedom to copy and change the  In the GNU project, we use copyleft to protect the four freedoms
253  software, even to <A HREF="/philosophy/selling.html">sell copies</A>.  legally for everyone.  We believe there are important reasons why
254  <P>  <a href="/philosophy/pragmatic.html">it is better to use
255    copyleft</a>.  However,
256  ``Free software'' does not mean ``non-commercial''.  A free program  <a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">
257  must be available for commercial use, commercial development, and  noncopylefted free software</a> is ethical
258  commercial distribution.  Commercial development of free software is  too.  See <a href="/philosophy/categories.html">Categories of Free
259  no longer unusual; such free commercial software is very important.  Software</a> for a description of how &ldquo;free software,&rdquo;
260    &ldquo;copylefted software&rdquo; and other categories of software
261  <P>  relate to each other.
262  Rules about how to package a modified version are acceptable, if they  </p>
263  don't effectively block your freedom to release modified versions.  
264  Rules that ``if you make the program available in this way, you must  <h4>Rules about packaging and distribution details</h4>
265  make it available in that way also'' can be acceptable too, on the  
266  same condition.  (Note that such a rule still leaves you the choice of  <p>
267  whether to publish the program or not.)  It is also acceptable for the  Rules about how to package a modified version are acceptable,
268  license to require that, if you have distributed a modified version  if they don't substantively limit your freedom to release modified
269  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.
270    Thus, it is acceptable for the license to require that you change the
271  <P>  name of the modified version, remove a logo, or identify your
272  In the GNU project, we use <A HREF="/copyleft/copyleft.html">  modifications as yours.  As long as these requirements are not so
273  ``copyleft''</A> to protect these freedoms legally for everyone.  But  burdensome that they effectively hamper you from releasing your
274  <A HREF="/philosophy/categories.html#Non-CopyleftedFreeSoftware">  changes, they are acceptable; you're already making other changes to
275  non-copylefted free software</A> also exists.  We believe there are  the program, so you won't have trouble making a few more.
276  important reasons why <A HREF="/philosophy/pragmatic.html"> it is  </p>
277  better to use copyleft</A>, but if your program is non-copylefted free  
278  software, we can still use it.  <p>
279    Rules that &ldquo;if you make your version available in this way, you
280  <P>  must make it available in that way also&rdquo; can be acceptable too,
281  See <A HREF="/philosophy/categories.html">Categories of Free Software  on the same condition.  An example of such an acceptable rule is one
282         (18k characters)</A>  saying that if you have distributed a
283  for a description of how ``free software,'' ``copylefted software'' and  modified version and a previous developer asks for a copy of it, you
284  other categories of software relate to each other.  must send one.  (Note that such a rule still leaves you the choice of
285    whether to distribute your version at all.)  Rules that require release
286  <P>  of source code to the users for versions that you put into public use
287  Sometimes government <A NAME="exportcontrol">export control  are also acceptable.
288  regulations</A> and trade sanctions can constrain your freedom to  </p>
289  distribute copies of programs internationally.  Software developers do  
290  not have the power to eliminate or override these restrictions, but  <p>
291  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
292  use of the program.  In this way, the restrictions will not affect  which the program will be invoked from other programs.  That
293  activities and people outside the jurisdictions of these governments.  effectively hampers you from releasing your changed version so that it
294    can replace the original when invoked by those other programs.  This
295  <P>  sort of requirement is acceptable only if there's a suitable aliasing
296  Most free software licenses are based on copyright, and there are  facility that allows you to specify the original program's name as an
297  limits on what kinds of requirements can be imposed through copyright.  alias for the modified version.</p>
298  If a copyright-based license respects freedom in the ways described  
299  above, it is unlikely to have some other sort of problem that we never  <h4>Export regulations</h4>
300  anticipated (though this does happen occasionally).  However, some  
301  free software licenses are based on contracts, and contracts can  <p>
302  impose a much larger range of possible restrictions.  That means there  Sometimes government <a id="exportcontrol">export control regulations</a>
303  are many possible ways such a license could be unacceptably  and trade sanctions can constrain your freedom to distribute copies of
304  restrictive and non-free.  programs internationally.  Software developers do not have the power to
305  <P>  eliminate or override these restrictions, but what they can and must do
306  We can't possibly list all the possible contract restrictions that  is refuse to impose them as conditions of use of the program.  In this
307  would be unacceptable.  If a contract-based license restricts the user  way, the restrictions will not affect activities and people outside the
308  in an unusual way that copyright-based licenses cannot, and which  jurisdictions of these governments.  Thus, free software licenses
309  isn't mentioned here as legitimate, we will have to think about it,  must not require obedience to any nontrivial export regulations as a
310  and we will probably decide it is non-free.  condition of exercising any of the essential freedoms.
311  <P>  </p>
312  When talking about free software, it is best to avoid using terms like  
313  ``give away'' or ``for free'', because those terms imply that the  <p>
314  issue is about price, not freedom.  Some common terms such as  Merely mentioning the existence of export regulations, without making
315  ``piracy'' embody opinions we hope you won't endorse.  See <A  them a condition of the license itself, is acceptable since it does
316  HREF="/philosophy/words-to-avoid.html">Confusing Words and Phrases  not restrict users.  If an export regulation is actually trivial for
317  that are Worth Avoiding</A> for a discussion of these terms.  free software, then requiring it as a condition is not an actual
318  We also have a list of <A HREF="/philosophy/fs-translations.html">translations  problem; however, it is a potential problem, since a later change in
319  of "free software"</A> into various languages.  export law could make the requirement nontrivial and thus render the
320    software nonfree.
321    </p>
322    
323    <h4>Legal considerations</h4>
324    
325    <p>
326    In order for these freedoms to be real, they must be permanent and
327    irrevocable as long as you do nothing wrong; if the developer of the
328    software has the power to revoke the license, or retroactively add
329    restrictions to its terms, without your doing anything wrong to give
330    cause, the software is not free.
331    </p>
332    
333    <p>
334    A free license may not require compliance with the license of a
335    nonfree program.  Thus, for instance, if a license requires you to
336    comply with the licenses of &ldquo;all the programs you use&rdquo;, in
337    the case of a user that runs nonfree programs this would require
338    compliance with the licenses of those nonfree programs; that makes the
339    license nonfree.
340    </p>
341    
342    <p>
343    It is acceptable for a free license to specify which jurisdiction's
344    law applies, or where litigation must be done, or both.
345    </p>
346    
347    <h4>Contract-based licenses</h4>
348    
349    <p>
350    Most free software licenses are based on copyright, and there are limits
351    on what kinds of requirements can be imposed through copyright.  If a
352    copyright-based license respects freedom in the ways described above, it
353    is unlikely to have some other sort of problem that we never anticipated
354    (though this does happen occasionally).  However, some free software
355    licenses are based on contracts, and contracts can impose a much larger
356    range of possible restrictions.  That means there are many possible ways
357    such a license could be unacceptably restrictive and nonfree.
358    </p>
359    
360    <p>
361    We can't possibly list all the ways that might happen.  If a
362    contract-based license restricts the user in an unusual way that
363    copyright-based licenses cannot, and which isn't mentioned here as
364    legitimate, we will have to think about it, and we will probably conclude
365    it is nonfree.
366    </p>
367    
368    <h4>Use the right words when talking about free software</h4>
369    
370    <p>
371    When talking about free software, it is best to avoid using terms
372    like &ldquo;give away&rdquo; or &ldquo;for free,&rdquo; because those terms imply that
373    the issue is about price, not freedom.  Some common terms such
374    as &ldquo;piracy&rdquo; embody opinions we hope you won't endorse.  See
375    <a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases that
376    are Worth Avoiding</a> for a discussion of these terms.  We also have
377    a list of proper <a href="/philosophy/fs-translations.html">translations of
378    &ldquo;free software&rdquo;</a> into various languages.
379    </p>
380    
381  <P>  <h4>How we interpret these criteria</h4>
382    
383    <p>
384  Finally, note that criteria such as those stated in this free software  Finally, note that criteria such as those stated in this free software
385  definition require careful thought for their interpretation.  To  definition require careful thought for their interpretation.  To decide
386  decide whether a specific software license qualifies as a free  whether a specific software license qualifies as a free software license,
387  software license, we judge it based on these criteria to determine  we judge it based on these criteria to determine whether it fits their
388  whether it fits their spirit as well as the precise words.  If a  spirit as well as the precise words.  If a license includes unconscionable
389  license includes unconscionable restrictions, we reject it, even if we  restrictions, we reject it, even if we did not anticipate the issue
390  did not anticipate the issue in these criteria.  Sometimes a license  in these criteria.  Sometimes a license requirement raises an issue
391  requirement raises an issue that calls for extensive thought,  that calls for extensive thought, including discussions with a lawyer,
392  including discussions with a lawyer, before we can decide if the  before we can decide if the requirement is acceptable.  When we reach
393  requirement is acceptable.  When we reach a conclusion about a new  a conclusion about a new issue, we often update these criteria to make
394  issue, we often update these criteria to make it easier to see why  it easier to see why certain licenses do or don't qualify.
395  certain licenses do or don't qualify.  </p>
396    
397  <P>  <h4>Get help with free licenses</h4>
398    
399  If you are interested in whether a specific license qualifies as a  <p>
400  free software license, see our <A  If you are interested in whether a specific license qualifies as a free
401  HREF="/licenses/license-list.html">list of licenses</A>.  If the  software license, see our <a href="/licenses/license-list.html">list
402  license you are concerned with is not listed there, you can ask us  of licenses</a>.  If the license you are concerned with is not
403  about it by sending us email at <A  listed there, you can ask us about it by sending us email at
404  HREF="mailto:licensing@gnu.org">&lt;licensing@gnu.org&gt;</A>.  <a href="mailto:licensing@gnu.org">&lt;licensing@gnu.org&gt;</a>.
405    </p>
406  <HR>  
407    <p>
408  <H4><A HREF="/philosophy/philosophy.html">Other Texts to Read</A></H4>  If you are contemplating writing a new license, please contact the
409    Free Software Foundation first by writing to that address. The
410  <P>  proliferation of different free software licenses means increased work
411  Another group has started using the term "open source" to mean  for users in understanding the licenses; we may be able to help you
412  something close (but not identical) to "free software".  We prefer the  find an existing free software license that meets your needs.
413  term "free software" because, once you have heard it refers to freedom  </p>
414  rather than price, <A HREF="free-software-for-freedom.html">it calls  
415  to mind freedom</A>.  <p>
416    If that isn't possible, if you really need a new license, with our
417  <HR>  help you can ensure that the license really is a free software license
418  [  and avoid various practical problems.
419  <!-- Please keep this list alphabetical -->  </p>
420  <!-- PLEASE UPDATE THE LIST AT THE BOTTOM (OR TOP) OF THE PAGE TOO! -->  
421  <A HREF="/philosophy/free-sw.hr.html">Croatian</A>  <h3 id="beyond-software">Beyond Software</h3>
422  | <A HREF="/philosophy/free-sw.cs.html">Czech</A>  
423  | <A HREF="/philosophy/free-sw.da.html">Danish</A>  <p>
424  | <A HREF="/philosophy/free-sw.nl.html">Dutch</A>  <a href="/philosophy/free-doc.html">Software manuals must be free</a>,
425  | <A HREF="/philosophy/free-sw.html">English</A>  for the same reasons that software must be free, and because the
426  | <A HREF="/philosophy/free-sw.fr.html">French</A>  manuals are in effect part of the software.
427  | <A HREF="/philosophy/free-sw.gl.html">Galician</A>  </p>
428  | <A HREF="/philosophy/free-sw.de.html">German</A>  
429  | <A HREF="/philosophy/free-sw.hu.html">Hungarian</A>  <p>
430  | <A HREF="/philosophy/free-sw.id.html">Indonesian</A>  The same arguments also make sense for other kinds of works of
431  | <A HREF="/philosophy/free-sw.it.html">Italian</A>  practical use &mdash; that is to say, works that embody useful knowledge,
432  | <A HREF="/philosophy/free-sw.ja.html">Japanese</A>  such as educational works and reference
433  | <A HREF="/philosophy/free-sw.ko.html">Korean</A>  works.  <a href="http://wikipedia.org">Wikipedia</a> is the best-known
434  | <A HREF="/philosophy/free-sw.no.html">Norwegian</A>  example.
435  | <A HREF="/philosophy/free-sw.pl.html">Polish</A>  </p>
436  | <A HREF="/philosophy/free-sw.pt.html">Portuguese</A>  
437  | <A HREF="/philosophy/free-sw.ro.html">Romanian</A>  <p>
438  | <A HREF="/philosophy/free-sw.ru.html">Russian</A>  Any kind of work <em>can</em> be free, and the definition of free software
439  | <A HREF="/philosophy/free-sw.sl.html">Slovenian</A>        has been extended to a definition of <a href="http://freedomdefined.org/">
440  | <A HREF="/philosophy/free-sw.es.html">Spanish</A>  free cultural works</a> applicable to any kind of works.
441  | <A HREF="/philosophy/free-sw.tr.html">Turkish</A>  </p>
442  <!-- Please keep this list alphabetical -->  
443  <!-- PLEASE UPDATE THE LIST AT THE BOTTOM (OR TOP) OF THE PAGE TOO! -->  <h3 id="open-source">Open Source?</h3>
444  ]  
445  <P>  <p>
446  Return to <A HREF="/home.html">GNU's home page</A>.  Another group uses the term &ldquo;open source&rdquo; to mean
447  <P>  something close (but not identical) to &ldquo;free software&rdquo;.  We
448    prefer the term &ldquo;free software&rdquo; because, once you have heard that
449  Please send FSF &amp; GNU inquiries &amp; questions to  it refers to freedom rather than price, it calls to mind freedom.  The
450    word &ldquo;open&rdquo; <a href="/philosophy/open-source-misses-the-point.html">
451  <A HREF="mailto:gnu@gnu.org"><EM>gnu@gnu.org</EM></A>.  never refers to freedom</a>.
452  There are also <A HREF="/home.html#ContactInfo">other ways to  </p>
453  contact</A> the FSF.  </div>
454  <P>  
455    <h3 id="History">History</h3>
456  Please send comments on these web pages to  
457    <p>From time to time we revise this Free Software Definition.  Here is
458  <A HREF="mailto:webmasters@gnu.org"><EM>webmasters@gnu.org</EM></A>,  the list of substantive changes, along with links to show exactly what
459  send other questions to  was changed.</p>
460  <A HREF="mailto:gnu@gnu.org"><EM>gnu@gnu.org</EM></A>.  
461  <P>  <ul>
462  Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, Free  
463  Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.164&amp;r2=1.165">Version
464  02111,  USA  1.165</a>: Clarify that arbitrary annoyances in the code do not
465  <P>  negate freedom 0, and that freedoms 1 and 3 enable users to remove them.</li>
466  Verbatim copying and distribution of this entire article is  
467  permitted in any medium, provided this notice is preserved.  <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.152&amp;r2=1.153">Version
468  <P>  1.153</a>: Clarify that freedom to run the program means nothing stops
469  Updated:  you from making it run.</li>
470    
471    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.140&amp;r2=1.141">Version
472    1.141</a>: Clarify which code needs to be free.</li>
473    
474    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.134&amp;r2=1.135">Version
475    1.135</a>: Say each time that freedom 0 is the freedom to run the program
476    as you wish.</li>
477    
478    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.133&amp;r2=1.134">Version
479    1.134</a>: Freedom 0 is not a matter of the program's functionality.</li>
480    
481    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.130&amp;r2=1.131">Version
482    1.131</a>: A free license may not require compliance with a nonfree license
483    of another program.</li>
484    
485    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.128&amp;r2=1.129">Version
486    1.129</a>: State explicitly that choice of law and choice of forum
487    specifications are allowed.  (This was always our policy.)</li>
488    
489    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.121&amp;r2=1.122">Version
490    1.122</a>: An export control requirement is a real problem if the
491    requirement is nontrivial; otherwise it is only a potential problem.</li>
492    
493    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.117&amp;r2=1.118">Version
494    1.118</a>: Clarification: the issue is limits on your right to modify,
495    not on what modifications you have made.  And modifications are not limited
496    to &ldquo;improvements&rdquo;</li>
497    
498    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.110&amp;r2=1.111">Version
499    1.111</a>: Clarify 1.77 by saying that only
500    retroactive <em>restrictions</em> are unacceptable.  The copyright
501    holders can always grant additional <em>permission</em> for use of the
502    work by releasing the work in another way in parallel.</li>
503    
504    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.104&amp;r2=1.105">Version
505    1.105</a>: Reflect, in the brief statement of freedom 1, the point
506    (already stated in version 1.80) that it includes really using your modified
507    version for your computing.</li>
508    
509    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.91&amp;r2=1.92">Version
510    1.92</a>: Clarify that obfuscated code does not qualify as source code.</li>
511    
512    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.89&amp;r2=1.90">Version
513    1.90</a>: Clarify that freedom 3 means the right to distribute copies
514    of your own modified or improved version, not a right to participate
515    in someone else's development project.</li>
516    
517    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.88&amp;r2=1.89">Version
518    1.89</a>: Freedom 3 includes the right to release modified versions as
519    free software.</li>
520    
521    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.79&amp;r2=1.80">Version
522    1.80</a>: Freedom 1 must be practical, not just theoretical;
523    i.e., no tivoization.</li>
524    
525    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.76&amp;r2=1.77">Version
526    1.77</a>: Clarify that all retroactive changes to the license are
527    unacceptable, even if it's not described as a complete
528    replacement.</li>
529    
530    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.73&amp;r2=1.74">Version
531    1.74</a>: Four clarifications of points not explicit enough, or stated
532    in some places but not reflected everywhere:
533    <ul>
534    <li>"Improvements" does not mean the license can
535    substantively limit what kinds of modified versions you can release.
536    Freedom 3 includes distributing modified versions, not just changes.</li>
537    <li>The right to merge in existing modules
538    refers to those that are suitably licensed.</li>
539    <li>Explicitly state the conclusion of the point about export controls.</li>
540    <li>Imposing a license change constitutes revoking the old license.</li>
541    </ul>
542    </li>
543    
544    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.56&amp;r2=1.57">Version
545    1.57</a>: Add &quot;Beyond Software&quot; section.</li>
546    
547    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.45&amp;r2=1.46">Version
548    1.46</a>: Clarify whose purpose is significant in the freedom to run
549    the program for any purpose.</li>
550    
551    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.40&amp;r2=1.41">Version
552    1.41</a>: Clarify wording about contract-based licenses.</li>
553    
554    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.39&amp;r2=1.40">Version
555    1.40</a>: Explain that a free license must allow to you use other
556    available free software to create your modifications.</li>
557    
558    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.38&amp;r2=1.39">Version
559    1.39</a>: Note that it is acceptable for a license to require you to
560    provide source for versions of the software you put into public
561    use.</li>
562    
563    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.30&amp;r2=1.31">Version
564    1.31</a>: Note that it is acceptable for a license to require you to
565    identify yourself as the author of modifications.  Other minor
566    clarifications throughout the text.</li>
567    
568    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.22&amp;r2=1.23">Version
569    1.23</a>: Address potential problems related to contract-based
570    licenses.</li>
571    
572    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.15&amp;r2=1.16">Version
573    1.16</a>: Explain why distribution of binaries is important.</li>
574    
575    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.10&amp;r2=1.11">Version
576    1.11</a>: Note that a free license may require you to send a copy of
577    versions you distribute to previous developers on request.</li>
578    
579    </ul>
580    
581    <p>There are gaps in the version numbers shown above because there are
582    other changes in this page that do not affect the definition or its
583    interpretations.  For instance, the list does not include changes in
584    asides, formatting, spelling, punctuation, or other parts of the page.
585    You can review the complete list of changes to the page through
586    the <a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;view=log">cvsweb
587    interface</a>.</p>
588    
589    <h3 style="font-size:1em">Footnote</h3>
590    <ol>
591    <li id="f1">The reason they are numbered 0, 1, 2 and 3 is historical. Around
592    1990 there were three freedoms, numbered 1, 2 and 3. Then we realized that
593    the freedom to run the program needed to be mentioned explicitly.
594    It was clearly more basic than the other three, so it properly should
595    precede them. Rather than renumber the others, we made it freedom&nbsp;0.</li>
596    </ol>
597    
598    </div><!-- for id="content", starts in the include above -->
599    <!--#include virtual="/server/footer.html" -->
600    <div id="footer">
601    <div class="unprintable">
602    
603    <p>Please send general FSF &amp; GNU inquiries to
604    <a href="mailto:gnu@gnu.org">&lt;gnu@gnu.org&gt;</a>.
605    There are also <a href="/contact/">other ways to contact</a>
606    the FSF.  Broken links and other corrections or suggestions can be sent
607    to <a href="mailto:webmasters@gnu.org">&lt;webmasters@gnu.org&gt;</a>.</p>
608    
609    <p><!-- TRANSLATORS: Ignore the original text in this paragraph,
610            replace it with the translation of these two:
611    
612            We work hard and do our best to provide accurate, good quality
613            translations.  However, we are not exempt from imperfection.
614            Please send your comments and general suggestions in this regard
615            to <a href="mailto:web-translators@gnu.org">
616            &lt;web-translators@gnu.org&gt;</a>.</p>
617    
618            <p>For information on coordinating and submitting translations of
619            our web pages, see <a
620            href="/server/standards/README.translations.html">Translations
621            README</a>. -->
622    Please see the <a
623    href="/server/standards/README.translations.html">Translations
624    README</a> for information on coordinating and submitting translations
625    of this article.</p>
626    </div>
627    
628    <!-- Regarding copyright, in general, standalone pages (as opposed to
629         files generated as part of manuals) on the GNU web server should
630         be under CC BY-ND 4.0.  Please do NOT change or remove this
631         without talking with the webmasters or licensing team first.
632         Please make sure the copyright date is consistent with the
633         document.  For web pages, it is ok to list just the latest year the
634         document was modified, or published.
635        
636         If you wish to list earlier years, that is ok too.
637         Either "2001, 2002, 2003" or "2001-2003" are ok for specifying
638         years, as long as each year in the range is in fact a copyrightable
639         year, i.e., a year in which the document was published (including
640         being publicly visible on the web or in a revision control system).
641        
642         There is more detail about copyright years in the GNU Maintainers
643         Information document, www.gnu.org/prep/maintain. -->
644    
645    <p>Copyright &copy; 1996, 2002, 2004-2007, 2009-2019
646    Free Software Foundation, Inc.</p>
647    
648    <p>This page is licensed under a <a rel="license"
649    href="http://creativecommons.org/licenses/by-nd/4.0/">Creative
650    Commons Attribution-NoDerivatives 4.0 International License</a>.</p>
651    
652    <!--#include virtual="/server/bottom-notes.html" -->
653    
654    <p class="unprintable">Updated:
655  <!-- timestamp start -->  <!-- timestamp start -->
656  $Date$ $Author$  $Date$
657  <!-- timestamp end -->  <!-- timestamp end -->
658  <HR>  </p>
659  </BODY>  </div>
660  </HTML>  </div><!-- for class="inner", starts in the banner include -->
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