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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 expain 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    <h4>The freedom to study the source code and make changes</h4>
158    
159    <p>
160    In order for freedoms 1 and 3 (the freedom to make changes and the
161    freedom to publish the changed versions) to be meaningful, you need to have
162    access to the source code of the program.  Therefore, accessibility of
163    source code is a necessary condition for free software.  Obfuscated
164    &ldquo;source code&rdquo; is not real source code and does not count
165    as source code.
166    </p>
167    
168    <p>
169    Freedom 1 includes the freedom to use your changed version in place of
170    the original.  If the program is delivered in a product designed to
171    run someone else's modified versions but refuse to run yours &mdash; a
172    practice known as &ldquo;tivoization&rdquo; or &ldquo;lockdown&rdquo;,
173    or (in its practitioners' perverse terminology) as &ldquo;secure
174    boot&rdquo; &mdash; freedom 1 becomes an empty pretense rather than a
175    practical reality.  These binaries are not free
176    software even if the source code they are compiled from is free.
177    </p>
178    
179    <p>
180    One important way to modify a program is by merging in available free
181    subroutines and modules.  If the program's license says that you
182    cannot merge in a suitably licensed existing module &mdash; for instance, if it
183    requires you to be the copyright holder of any code you add &mdash; then the
184    license is too restrictive to qualify as free.
185    </p>
186    
187    <p>
188    Whether a change constitutes an improvement is a subjective matter.
189    If your right to modify a program is limited, in substance, to changes that
190    someone else considers an improvement, that program is not free.
191    </p>
192    
193    <h4>The freedom to redistribute if you wish: basic requirements</h4>
194    
195    <p>Freedom to distribute (freedoms 2 and 3) means you are free to
196    redistribute copies, either with or without modifications, either
197    gratis or charging a fee for distribution, to
198    <a href="#exportcontrol">anyone anywhere</a>.  Being free to do these
199    things means (among other things) that you do not have to ask or pay
200    for permission to do so.
201    </p>
202    
203  <P>  <p>
204  You should also have the freedom to make modifications and use them  You should also have the freedom to make modifications and use them
205  privately in your own work or play, without even mentioning that they  privately in your own work or play, without even mentioning that they
206  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
207  notify anyone in particular, or in any particular way.  notify anyone in particular, or in any particular way.
208    </p>
209    
210  <P>  <p>
211  The freedom to use a program means the freedom for any kind of person  Freedom 3 includes the freedom to release your modified versions
212  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
213  of overall job, and without being required to communicate subsequently  releasing them; in other words, it does not have to be
214  with the developer or any other specific entity.  a <a href="/copyleft/copyleft.html">copyleft</a> license.  However, a
215    license that requires modified versions to be nonfree does not qualify
216    as a free license.
217    </p>
218    
219  <P>  <p>
220  The freedom to redistribute copies must include binary or executable  The freedom to redistribute copies must include binary or executable
221  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
222  unmodified versions.  (Distributing programs in runnable form is  unmodified versions.  (Distributing programs in runnable form is necessary
223  necessary for conveniently installable free operating systems.)  It is  for conveniently installable free operating systems.)  It is OK if there
224  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
225  certain program (since some languages don't support that feature), but  (since some languages don't support that feature), but you must have the
226  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
227  or develop a way to make them.  make them.
228    </p>
229  <P>  
230  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.  
231    
232  <P>  <p>
233  However, certain kinds of rules about the manner of distributing free  Certain kinds of rules about the manner of distributing free
234  software are acceptable, when they don't conflict with the central  software are acceptable, when they don't conflict with the central
235  freedoms.  For example, copyleft (very simply stated) is the rule that  freedoms.  For example, <a href="/copyleft/copyleft.html">copyleft</a>
236  when redistributing the program, you cannot add restrictions to deny  (very simply stated) is the rule that when redistributing the program,
237  other people the central freedoms.  This rule does not conflict with  you cannot add restrictions to deny other people the central freedoms.
238  the central freedoms; rather it protects them.  This rule does not conflict with the central freedoms; rather it
239    protects them.
240  <P>  </p>
241  Thus, you may have paid money to get copies of free software, or you  
242  may have obtained copies at no charge.  But regardless of how you got  <p>
243  your copies, you always have the freedom to copy and change the  In the GNU project, we use copyleft to protect the four freedoms
244  software, even to <A HREF="/philosophy/selling.html">sell copies</A>.  legally for everyone.  We believe there are important reasons why
245  <P>  <a href="/philosophy/pragmatic.html">it is better to use
246    copyleft</a>.  However,
247  ``Free software'' does not mean ``non-commercial''.  A free program  <a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">
248  must be available for commercial use, commercial development, and  noncopylefted free software</a> is ethical
249  commercial distribution.  Commercial development of free software is  too.  See <a href="/philosophy/categories.html">Categories of Free
250  no longer unusual; such free commercial software is very important.  Software</a> for a description of how &ldquo;free software,&rdquo;
251    &ldquo;copylefted software&rdquo; and other categories of software
252  <P>  relate to each other.
253  Rules about how to package a modified version are acceptable, if they  </p>
254  don't effectively block your freedom to release modified versions.  
255  Rules that ``if you make the program available in this way, you must  <h4>Rules about packaging and distribution details</h4>
256  make it available in that way also'' can be acceptable too, on the  
257  same condition.  (Note that such a rule still leaves you the choice of  <p>
258  whether to publish the program or not.)  It is also acceptable for the  Rules about how to package a modified version are acceptable,
259  license to require that, if you have distributed a modified version  if they don't substantively limit your freedom to release modified
260  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.
261    Thus, it is acceptable for the license to require that you change the
262  <P>  name of the modified version, remove a logo, or identify your
263  In the GNU project, we use <A HREF="/copyleft/copyleft.html">  modifications as yours.  As long as these requirements are not so
264  ``copyleft''</A> to protect these freedoms legally for everyone.  But  burdensome that they effectively hamper you from releasing your
265  <A HREF="/philosophy/categories.html#Non-CopyleftedFreeSoftware">  changes, they are acceptable; you're already making other changes to
266  non-copylefted free software</A> also exists.  We believe there are  the program, so you won't have trouble making a few more.
267  important reasons why <A HREF="/philosophy/pragmatic.html"> it is  </p>
268  better to use copyleft</A>, but if your program is non-copylefted free  
269  software, we can still use it.  <p>
270    Rules that &ldquo;if you make your version available in this way, you
271  <P>  must make it available in that way also&rdquo; can be acceptable too,
272  See <A HREF="/philosophy/categories.html">Categories of Free Software  on the same condition.  An example of such an acceptable rule is one
273         (18k characters)</A>  saying that if you have distributed a
274  for a description of how ``free software,'' ``copylefted software'' and  modified version and a previous developer asks for a copy of it, you
275  other categories of software relate to each other.  must send one.  (Note that such a rule still leaves you the choice of
276    whether to distribute your version at all.)  Rules that require release
277  <P>  of source code to the users for versions that you put into public use
278  Sometimes government <A NAME="exportcontrol">export control  are also acceptable.
279  regulations</A> and trade sanctions can constrain your freedom to  </p>
280  distribute copies of programs internationally.  Software developers do  
281  not have the power to eliminate or override these restrictions, but  <p>
282  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
283  use of the program.  In this way, the restrictions will not affect  which the program will be invoked from other programs.  That
284  activities and people outside the jurisdictions of these governments.  effectively hampers you from releasing your changed version so that it
285    can replace the original when invoked by those other programs.  This
286  <P>  sort of requirement is acceptable only if there's a suitable aliasing
287  Most free software licenses are based on copyright, and there are  facility that allows you to specify the original program's name as an
288  limits on what kinds of requirements can be imposed through copyright.  alias for the modified version.</p>
289  If a copyright-based license respects freedom in the ways described  
290  above, it is unlikely to have some other sort of problem that we never  <h4>Export regulations</h4>
291  anticipated (though this does happen occasionally).  However, some  
292  free software licenses are based on contracts, and contracts can  <p>
293  impose a much larger range of possible restrictions.  That means there  Sometimes government <a id="exportcontrol">export control regulations</a>
294  are many possible ways such a license could be unacceptably  and trade sanctions can constrain your freedom to distribute copies of
295  restrictive and non-free.  programs internationally.  Software developers do not have the power to
296  <P>  eliminate or override these restrictions, but what they can and must do
297  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
298  would be unacceptable.  If a contract-based license restricts the user  way, the restrictions will not affect activities and people outside the
299  in an unusual way that copyright-based licenses cannot, and which  jurisdictions of these governments.  Thus, free software licenses
300  isn't mentioned here as legitimate, we will have to think about it,  must not require obedience to any nontrivial export regulations as a
301  and we will probably decide it is non-free.  condition of exercising any of the essential freedoms.
302  <P>  </p>
303  When talking about free software, it is best to avoid using terms like  
304  ``give away'' or ``for free'', because those terms imply that the  <p>
305  issue is about price, not freedom.  Some common terms such as  Merely mentioning the existence of export regulations, without making
306  ``piracy'' embody opinions we hope you won't endorse.  See <A  them a condition of the license itself, is acceptable since it does
307  HREF="/philosophy/words-to-avoid.html">Confusing Words and Phrases  not restrict users.  If an export regulation is actually trivial for
308  that are Worth Avoiding</A> for a discussion of these terms.  free software, then requiring it as a condition is not an actual
309  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
310  of "free software"</A> into various languages.  export law could make the requirement nontrivial and thus render the
311    software nonfree.
312    </p>
313    
314    <h4>Legal considerations</h4>
315    
316    <p>
317    In order for these freedoms to be real, they must be permanent and
318    irrevocable as long as you do nothing wrong; if the developer of the
319    software has the power to revoke the license, or retroactively add
320    restrictions to its terms, without your doing anything wrong to give
321    cause, the software is not free.
322    </p>
323    
324    <p>
325    A free license may not require compliance with the license of a
326    nonfree program.  Thus, for instance, if a license requires you to
327    comply with the licenses of &ldquo;all the programs you use&rdquo;, in
328    the case of a user that runs nonfree programs this would require
329    compliance with the licenses of those nonfree programs; that makes the
330    license nonfree.
331    </p>
332    
333    <p>
334    It is acceptable for a free license to specify which jurisdiction's
335    law applies, or where litigation must be done, or both.
336    </p>
337    
338    <h4>Contract-based licenses</h4>
339    
340    <p>
341    Most free software licenses are based on copyright, and there are limits
342    on what kinds of requirements can be imposed through copyright.  If a
343    copyright-based license respects freedom in the ways described above, it
344    is unlikely to have some other sort of problem that we never anticipated
345    (though this does happen occasionally).  However, some free software
346    licenses are based on contracts, and contracts can impose a much larger
347    range of possible restrictions.  That means there are many possible ways
348    such a license could be unacceptably restrictive and nonfree.
349    </p>
350    
351    <p>
352    We can't possibly list all the ways that might happen.  If a
353    contract-based license restricts the user in an unusual way that
354    copyright-based licenses cannot, and which isn't mentioned here as
355    legitimate, we will have to think about it, and we will probably conclude
356    it is nonfree.
357    </p>
358    
359    <h4>Use the right words when talking about free software</h4>
360    
361    <p>
362    When talking about free software, it is best to avoid using terms
363    like &ldquo;give away&rdquo; or &ldquo;for free,&rdquo; because those terms imply that
364    the issue is about price, not freedom.  Some common terms such
365    as &ldquo;piracy&rdquo; embody opinions we hope you won't endorse.  See
366    <a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases that
367    are Worth Avoiding</a> for a discussion of these terms.  We also have
368    a list of proper <a href="/philosophy/fs-translations.html">translations of
369    &ldquo;free software&rdquo;</a> into various languages.
370    </p>
371    
372  <P>  <h4>How we interpret these criteria</h4>
373    
374    <p>
375  Finally, note that criteria such as those stated in this free software  Finally, note that criteria such as those stated in this free software
376  definition require careful thought for their interpretation.  To  definition require careful thought for their interpretation.  To decide
377  decide whether a specific software license qualifies as a free  whether a specific software license qualifies as a free software license,
378  software license, we judge it based on these criteria to determine  we judge it based on these criteria to determine whether it fits their
379  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
380  license includes unconscionable restrictions, we reject it, even if we  restrictions, we reject it, even if we did not anticipate the issue
381  did not anticipate the issue in these criteria.  Sometimes a license  in these criteria.  Sometimes a license requirement raises an issue
382  requirement raises an issue that calls for extensive thought,  that calls for extensive thought, including discussions with a lawyer,
383  including discussions with a lawyer, before we can decide if the  before we can decide if the requirement is acceptable.  When we reach
384  requirement is acceptable.  When we reach a conclusion about a new  a conclusion about a new issue, we often update these criteria to make
385  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.
386  certain licenses do or don't qualify.  </p>
387    
388  <P>  <h4>Get help with free licenses</h4>
389    
390  If you are interested in whether a specific license qualifies as a  <p>
391  free software license, see our <A  If you are interested in whether a specific license qualifies as a free
392  HREF="/licenses/license-list.html">list of licenses</A>.  If the  software license, see our <a href="/licenses/license-list.html">list
393  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
394  about it by sending us email at <A  listed there, you can ask us about it by sending us email at
395  HREF="mailto:licensing@gnu.org">&lt;licensing@gnu.org&gt;</A>.  <a href="mailto:licensing@gnu.org">&lt;licensing@gnu.org&gt;</a>.
396    </p>
397  <HR>  
398    <p>
399  <H4><A HREF="/philosophy/philosophy.html">Other Texts to Read</A></H4>  If you are contemplating writing a new license, please contact the
400    Free Software Foundation first by writing to that address. The
401  <P>  proliferation of different free software licenses means increased work
402  Another group has started using the term "open source" to mean  for users in understanding the licenses; we may be able to help you
403  something close (but not identical) to "free software".  We prefer the  find an existing free software license that meets your needs.
404  term "free software" because, once you have heard it refers to freedom  </p>
405  rather than price, <A HREF="free-software-for-freedom.html">it calls  
406  to mind freedom</A>.  <p>
407    If that isn't possible, if you really need a new license, with our
408  <HR>  help you can ensure that the license really is a free software license
409  [  and avoid various practical problems.
410  <!-- Please keep this list alphabetical -->  </p>
411  <!-- PLEASE UPDATE THE LIST AT THE BOTTOM (OR TOP) OF THE PAGE TOO! -->  
412  <A HREF="/philosophy/free-sw.hr.html">Croatian</A>  <h3 id="beyond-software">Beyond Software</h3>
413  | <A HREF="/philosophy/free-sw.cs.html">Czech</A>  
414  | <A HREF="/philosophy/free-sw.da.html">Danish</A>  <p>
415  | <A HREF="/philosophy/free-sw.nl.html">Dutch</A>  <a href="/philosophy/free-doc.html">Software manuals must be free</a>,
416  | <A HREF="/philosophy/free-sw.html">English</A>  for the same reasons that software must be free, and because the
417  | <A HREF="/philosophy/free-sw.fr.html">French</A>  manuals are in effect part of the software.
418  | <A HREF="/philosophy/free-sw.gl.html">Galician</A>  </p>
419  | <A HREF="/philosophy/free-sw.de.html">German</A>  
420  | <A HREF="/philosophy/free-sw.hu.html">Hungarian</A>  <p>
421  | <A HREF="/philosophy/free-sw.id.html">Indonesian</A>  The same arguments also make sense for other kinds of works of
422  | <A HREF="/philosophy/free-sw.it.html">Italian</A>  practical use &mdash; that is to say, works that embody useful knowledge,
423  | <A HREF="/philosophy/free-sw.ja.html">Japanese</A>  such as educational works and reference
424  | <A HREF="/philosophy/free-sw.ko.html">Korean</A>  works.  <a href="http://wikipedia.org">Wikipedia</a> is the best-known
425  | <A HREF="/philosophy/free-sw.no.html">Norwegian</A>  example.
426  | <A HREF="/philosophy/free-sw.pl.html">Polish</A>  </p>
427  | <A HREF="/philosophy/free-sw.pt.html">Portuguese</A>  
428  | <A HREF="/philosophy/free-sw.ro.html">Romanian</A>  <p>
429  | <A HREF="/philosophy/free-sw.ru.html">Russian</A>  Any kind of work <em>can</em> be free, and the definition of free software
430  | <A HREF="/philosophy/free-sw.sl.html">Slovenian</A>        has been extended to a definition of <a href="http://freedomdefined.org/">
431  | <A HREF="/philosophy/free-sw.es.html">Spanish</A>  free cultural works</a> applicable to any kind of works.
432  | <A HREF="/philosophy/free-sw.tr.html">Turkish</A>  </p>
433  <!-- Please keep this list alphabetical -->  
434  <!-- PLEASE UPDATE THE LIST AT THE BOTTOM (OR TOP) OF THE PAGE TOO! -->  <h3 id="open-source">Open Source?</h3>
435  ]  
436  <P>  <p>
437  Return to <A HREF="/home.html">GNU's home page</A>.  Another group uses the term &ldquo;open source&rdquo; to mean
438  <P>  something close (but not identical) to &ldquo;free software&rdquo;.  We
439    prefer the term &ldquo;free software&rdquo; because, once you have heard that
440  Please send FSF &amp; GNU inquiries &amp; questions to  it refers to freedom rather than price, it calls to mind freedom.  The
441    word &ldquo;open&rdquo; <a href="/philosophy/open-source-misses-the-point.html">
442  <A HREF="mailto:gnu@gnu.org"><EM>gnu@gnu.org</EM></A>.  never refers to freedom</a>.
443  There are also <A HREF="/home.html#ContactInfo">other ways to  </p>
444  contact</A> the FSF.  </div>
445  <P>  
446    <h3 id="History">History</h3>
447  Please send comments on these web pages to  
448    <p>From time to time we revise this Free Software Definition.  Here is
449  <A HREF="mailto:webmasters@gnu.org"><EM>webmasters@gnu.org</EM></A>,  the list of substantive changes, along with links to show exactly what
450  send other questions to  was changed.</p>
451  <A HREF="mailto:gnu@gnu.org"><EM>gnu@gnu.org</EM></A>.  
452  <P>  <ul>
453  Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, Free  
454  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=1.162&amp;r2=1.163">Version
455  02111,  USA  1.163</a>: Clarify that the four freedoms apply to any and all users,
456  <P>  and that requiring users to pay to exercise some of these freedoms is
457  Verbatim copying and distribution of this entire article is  a way of denying them.</li>
458  permitted in any medium, provided this notice is preserved.  
459  <P>  <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
460  Updated:  1.153</a>: Clarify that freedom to run the program means nothing stops
461    you from making it run.</li>
462    
463    <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
464    1.141</a>: Clarify which code needs to be free.</li>
465    
466    <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
467    1.135</a>: Say each time that freedom 0 is the freedom to run the program
468    as you wish.</li>
469    
470    <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
471    1.134</a>: Freedom 0 is not a matter of the program's functionality.</li>
472    
473    <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
474    1.131</a>: A free license may not require compliance with a nonfree license
475    of another program.</li>
476    
477    <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
478    1.129</a>: State explicitly that choice of law and choice of forum
479    specifications are allowed.  (This was always our policy.)</li>
480    
481    <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
482    1.122</a>: An export control requirement is a real problem if the
483    requirement is nontrivial; otherwise it is only a potential problem.</li>
484    
485    <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
486    1.118</a>: Clarification: the issue is limits on your right to modify,
487    not on what modifications you have made.  And modifications are not limited
488    to &ldquo;improvements&rdquo;</li>
489    
490    <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
491    1.111</a>: Clarify 1.77 by saying that only
492    retroactive <em>restrictions</em> are unacceptable.  The copyright
493    holders can always grant additional <em>permission</em> for use of the
494    work by releasing the work in another way in parallel.</li>
495    
496    <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
497    1.105</a>: Reflect, in the brief statement of freedom 1, the point
498    (already stated in version 1.80) that it includes really using your modified
499    version for your computing.</li>
500    
501    <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
502    1.92</a>: Clarify that obfuscated code does not qualify as source code.</li>
503    
504    <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
505    1.90</a>: Clarify that freedom 3 means the right to distribute copies
506    of your own modified or improved version, not a right to participate
507    in someone else's development project.</li>
508    
509    <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
510    1.89</a>: Freedom 3 includes the right to release modified versions as
511    free software.</li>
512    
513    <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
514    1.80</a>: Freedom 1 must be practical, not just theoretical;
515    i.e., no tivoization.</li>
516    
517    <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
518    1.77</a>: Clarify that all retroactive changes to the license are
519    unacceptable, even if it's not described as a complete
520    replacement.</li>
521    
522    <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
523    1.74</a>: Four clarifications of points not explicit enough, or stated
524    in some places but not reflected everywhere:
525    <ul>
526    <li>"Improvements" does not mean the license can
527    substantively limit what kinds of modified versions you can release.
528    Freedom 3 includes distributing modified versions, not just changes.</li>
529    <li>The right to merge in existing modules
530    refers to those that are suitably licensed.</li>
531    <li>Explicitly state the conclusion of the point about export controls.</li>
532    <li>Imposing a license change constitutes revoking the old license.</li>
533    </ul>
534    </li>
535    
536    <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
537    1.57</a>: Add &quot;Beyond Software&quot; section.</li>
538    
539    <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
540    1.46</a>: Clarify whose purpose is significant in the freedom to run
541    the program for any purpose.</li>
542    
543    <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
544    1.41</a>: Clarify wording about contract-based licenses.</li>
545    
546    <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
547    1.40</a>: Explain that a free license must allow to you use other
548    available free software to create your modifications.</li>
549    
550    <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
551    1.39</a>: Note that it is acceptable for a license to require you to
552    provide source for versions of the software you put into public
553    use.</li>
554    
555    <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
556    1.31</a>: Note that it is acceptable for a license to require you to
557    identify yourself as the author of modifications.  Other minor
558    clarifications throughout the text.</li>
559    
560    <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
561    1.23</a>: Address potential problems related to contract-based
562    licenses.</li>
563    
564    <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
565    1.16</a>: Explain why distribution of binaries is important.</li>
566    
567    <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
568    1.11</a>: Note that a free license may require you to send a copy of
569    versions you distribute to previous developers on request.</li>
570    
571    </ul>
572    
573    <p>There are gaps in the version numbers shown above because there are
574    other changes in this page that do not affect the definition or its
575    interpretations.  For instance, the list does not include changes in
576    asides, formatting, spelling, punctuation, or other parts of the page.
577    You can review the complete list of changes to the page through
578    the <a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;view=log">cvsweb
579    interface</a>.</p>
580    
581    <h3 style="font-size:1em">Footnote</h3>
582    <ol>
583    <li id="f1">The reason they are numbered 0, 1, 2 and 3 is historical. Around
584    1990 there were three freedoms, numbered 1, 2 and 3. Then we realized that
585    the freedom to run the program needed to be mentioned explicitly.
586    It was clearly more basic than the other three, so it properly should
587    precede them. Rather than renumber the others, we made it freedom&nbsp;0.</li>
588    </ol>
589    
590    </div><!-- for id="content", starts in the include above -->
591    <!--#include virtual="/server/footer.html" -->
592    <div id="footer">
593    <div class="unprintable">
594    
595    <p>Please send general FSF &amp; GNU inquiries to
596    <a href="mailto:gnu@gnu.org">&lt;gnu@gnu.org&gt;</a>.
597    There are also <a href="/contact/">other ways to contact</a>
598    the FSF.  Broken links and other corrections or suggestions can be sent
599    to <a href="mailto:webmasters@gnu.org">&lt;webmasters@gnu.org&gt;</a>.</p>
600    
601    <p><!-- TRANSLATORS: Ignore the original text in this paragraph,
602            replace it with the translation of these two:
603    
604            We work hard and do our best to provide accurate, good quality
605            translations.  However, we are not exempt from imperfection.
606            Please send your comments and general suggestions in this regard
607            to <a href="mailto:web-translators@gnu.org">
608            &lt;web-translators@gnu.org&gt;</a>.</p>
609    
610            <p>For information on coordinating and submitting translations of
611            our web pages, see <a
612            href="/server/standards/README.translations.html">Translations
613            README</a>. -->
614    Please see the <a
615    href="/server/standards/README.translations.html">Translations
616    README</a> for information on coordinating and submitting translations
617    of this article.</p>
618    </div>
619    
620    <!-- Regarding copyright, in general, standalone pages (as opposed to
621         files generated as part of manuals) on the GNU web server should
622         be under CC BY-ND 4.0.  Please do NOT change or remove this
623         without talking with the webmasters or licensing team first.
624         Please make sure the copyright date is consistent with the
625         document.  For web pages, it is ok to list just the latest year the
626         document was modified, or published.
627        
628         If you wish to list earlier years, that is ok too.
629         Either "2001, 2002, 2003" or "2001-2003" are ok for specifying
630         years, as long as each year in the range is in fact a copyrightable
631         year, i.e., a year in which the document was published (including
632         being publicly visible on the web or in a revision control system).
633        
634         There is more detail about copyright years in the GNU Maintainers
635         Information document, www.gnu.org/prep/maintain. -->
636    
637    <p>Copyright &copy; 1996, 2002, 2004-2007, 2009-2019
638    Free Software Foundation, Inc.</p>
639    
640    <p>This page is licensed under a <a rel="license"
641    href="http://creativecommons.org/licenses/by-nd/4.0/">Creative
642    Commons Attribution-NoDerivatives 4.0 International License</a>.</p>
643    
644    <!--#include virtual="/server/bottom-notes.html" -->
645    
646    <p class="unprintable">Updated:
647  <!-- timestamp start -->  <!-- timestamp start -->
648  $Date$ $Author$  $Date$
649  <!-- timestamp end -->  <!-- timestamp end -->
650  <HR>  </p>
651  </BODY>  </div>
652  </HTML>  </div><!-- for class="inner", starts in the banner include -->
653    </body>
654    </html>
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