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7    - GNU Project - Free Software Foundation</title>
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22    <h2>What is Free Software?</h2>
23    <div class="thin"></div>
24    
25    <div class="article">
26    <div class="important">
27    <p>
28    &ldquo;Free software&rdquo; means software that respects users'
29    freedom and community.  Roughly, it means that <b>the users have the
30    freedom to run, copy, distribute, study, change and improve the
31    software</b>.  Thus, &ldquo;free software&rdquo; is a matter of
32    liberty, not price.  To understand the concept, you should think of
33    &ldquo;free&rdquo; as in &ldquo;free speech,&rdquo; not as in
34    &ldquo;free beer&rdquo;.  We sometimes call it &ldquo;libre
35    software,&rdquo; borrowing the French or Spanish word for
36    &ldquo;free&rdquo; as in freedom, to show we do not mean the software
37    is gratis.
38    </p>
39    
40  <h1>The Free Software Definition</h1>  <p>
41    You may have paid money to get copies of a free program, or you may
42    have obtained copies at no charge.  But regardless of how you got your
43    copies, you always have the freedom to copy and change the software,
44    even to <a href="/philosophy/selling.html">sell copies</a>.
45    </p>
46    </div>
47    
48  <p>  <p>
49  We maintain this free software definition to show clearly what must  We campaign for these freedoms because everyone deserves them.  With
50  be true about a particular software program for it to be considered  these freedoms, the users (both individually and collectively) control
51  free software.  the program and what it does for them.  When users don't control the
52    program, we call it a &ldquo;nonfree&rdquo; or
53    &ldquo;proprietary&rdquo; program.  The nonfree program controls the
54    users, and the developer controls the program; this makes the
55    program <a href="/philosophy/free-software-even-more-important.html">
56    an instrument of unjust power</a>.
57  </p>  </p>
58    
59  <p>  <p>
60  <q>Free software</q> is a matter of liberty, not price.  To understand  &ldquo;Open source&rdquo; is something different: it has a very
61  the concept, you should think of <q>free</q> as in <q>free speech,</q>  different philosophy based on different values.  Its practical
62  not as in <q>free beer.</q>  definition is different too, but nearly all open source programs are
63    in fact free.  We explain the
64    difference in <a href="/philosophy/open-source-misses-the-point.html">
65    Why &ldquo;Open Source&rdquo; misses the point of Free Software</a>.
66    </p>
67    
68    <div class="toc">
69    <hr class="no-display" />
70    <h3 class="no-display">Table of contents</h3>
71    <ul>
72     <li><a href="#fs-definition">The Free Software Definition</a>
73      <ul>
74       <li><a href="#four-freedoms">The four essential freedoms</a></li>
75       <li><a href="#selling">Free software <em>can</em> be commercial</a></li>
76      </ul>
77     </li>
78     <li><a href="#clarifying">Clarifying the Boundary Between Free and Nonfree</a>
79      <ul>
80       <li><a href="#run-the-program">The freedom to run the program as you
81         wish</a></li>
82       <li><a href="#make-changes">The freedom to study the source code and make
83         changes</a></li>
84       <li><a href="#redistribute">The freedom to redistribute if you wish:
85         basic requirements</a></li>
86       <li><a href="#copyleft">Copyleft</a></li>
87       <li><a href="#packaging">Rules about packaging and distribution
88         details</a></li>
89       <li><a href="#exportcontrol">Export regulations</a></li>
90       <li><a href="#legal-details">Legal considerations</a></li>
91       <li><a href="#contracts">Contract-based licenses</a></li>
92      </ul>
93     </li>
94     <li><a href="#in-practice">The Free Software Definition in Practice</a>
95      <ul>
96       <li><a href="#interpretation">How we interpret these criteria</a></li>
97       <li><a href="#get-help">Get help with free licenses</a></li>
98       <li><a href="#terminology">Use the right words when talking about free
99         software</a></li>
100      </ul>
101     </li>
102     <li><a href="#beyond-software">Beyond Software</a></li>
103     <li><a href="#History">History</a></li>
104    </ul>
105    </div>
106    
107    <div class="edu-note" id="fsf-licensing">
108    <p style="font-size:80%">
109    Have a question about free software licensing not answered here?
110    See our other <a href="http://www.fsf.org/licensing">licensing resources</a>,
111    and if necessary contact the FSF Compliance Lab
112    at <a href="mailto:licensing@fsf.org">licensing@fsf.org</a>.</p>
113    <hr class="no-display" />
114    </div>
115    
116    
117    <h3 id="fs-definition" class="subheader">The Free Software Definition</h3>
118    
119    <p>
120    The free software definition presents the criteria for whether a
121    particular software program qualifies as free software.  From time to
122    time we revise this definition, to clarify it or to resolve questions
123    about subtle issues.  See the <a href="#History">History section</a>
124    below for a list of changes that affect the definition of free
125    software.
126  </p>  </p>
127    
128    <h4 id="four-freedoms">The four essential freedoms</h4>
129  <p>  <p>
130  Free software is a matter of the users' freedom to run, copy, distribute,  A program is free software if the program's users have the
131  study, change and improve the software.  More precisely, it refers to  four essential freedoms: <a href="#f1">[1]</a>
 four kinds of freedom, for the users of the software:  
132  </p>  </p>
133    
134  <ul>  <ul class="important">
135    <li>The freedom to run the program, for any purpose (freedom 0).</li>    <li>The freedom to run the program as you wish,
136    <li>The freedom to study how the program works, and adapt it to        for any purpose (freedom 0).</li>
137        your needs (freedom 1). Access to the source code is a precondition    <li>The freedom to study how the program works, and change it so it
138        for this.        does your computing as you wish (freedom 1). Access to the source
139          code is a precondition for this.
140    </li>    </li>
141    <li>The freedom to redistribute copies so you can help your neighbor    <li>The freedom to redistribute copies so you can help others
142        (freedom 2).        (freedom 2).
143    </li>    </li>
144    <li>The freedom to improve the program, and release your improvements    <li>The freedom to distribute copies of your modified versions
145        to the public, so that the whole community benefits (freedom 3).        to others (freedom 3).  By doing this you can give the whole
146          community a chance to benefit from your changes.
147        Access to the source code is a precondition for this.        Access to the source code is a precondition for this.
148    </li>    </li>
149  </ul>  </ul>
150    
151  <p>  <p>
152  A program is free software if users have all of these freedoms.  Thus,  A program is free software if it gives users adequately all of these
153  you should be free to redistribute copies, either with or without  freedoms.  Otherwise, it is nonfree.  While we can distinguish various
154  modifications, either gratis or charging a fee for distribution, to  nonfree distribution schemes in terms of how far they fall short of
155  <a href="#exportcontrol">anyone anywhere</a>.  Being free to do these  being free, we consider them all equally unethical.</p>
156  things means (among other things) that you do not have to ask or pay  
157  for permission.  <p>In any given scenario, these freedoms must apply to whatever code
158    we plan to make use of, or lead others to make use of.  For instance,
159    consider a program A which automatically launches a program B to
160    handle some cases.  If we plan to distribute A as it stands, that
161    implies users will need B, so we need to judge whether both A and B
162    are free.  However, if we plan to modify A so that it doesn't use B,
163    only A needs to be free; B is not pertinent to that plan.</p>
164    
165    
166    <h4 id="selling">Free software <em>can</em> be commercial</h4>
167    
168    <p>
169    &ldquo;Free software&rdquo; does not mean &ldquo;noncommercial&rdquo;.
170    On the contrary, a free program must be available for commercial use,
171    commercial development, and commercial distribution.  This policy is
172    of fundamental importance&mdash;without this, free software could not
173    achieve its aims.
174  </p>  </p>
175    
176  <p>  <p>
177  You should also have the freedom to make modifications and use them  We want to invite everyone to use the GNU system, including businesses
178  privately in your own work or play, without even mentioning that they  and their workers.  That requires allowing commercial use.  We hope
179  exist.  If you do publish your changes, you should not be required to  that free replacement programs will supplant comparable proprietary
180  notify anyone in particular, or in any particular way.  programs, but they can't do that if businesses are forbidden to use
181    them.  We want commercial products that contain software to include
182    the GNU system, and that would constitute commercial distribution for
183    a price.  Commercial development of free software is no longer
184    unusual; such free commercial software is very important.  Paid,
185    professional support for free software fills an important need.
186    </p>
187    
188    <p>
189    Thus, to exclude commercial use, commercial development or commercial
190    distribution would hobble the free software community and obstruct its
191    path to success.  We must conclude that a program licensed with such
192    restrictions does not qualify as free software.
193  </p>  </p>
194    
195  <p>  <p>
196    A free program must offer the four freedoms to any would-be user that
197    obtains a copy of the software, who has complied thus far with the
198    conditions of the free license covering the software in any previous
199    distribution of it.  Putting some of the freedoms off limits to some
200    users, or requiring that users pay, in money or in kind, to exercise
201    them, is tantamount to not granting the freedoms in question, and thus
202    renders the program nonfree.
203    </p>
204    
205    
206    <h3 id="clarifying" class="subheader">Clarifying the Boundary Between Free and Nonfree</h3>
207    
208    <p>In the rest of this article we explain more precisely how far the
209    various freedoms need to extend, on various issues, in order for a
210    program to be free.</p>
211    
212    <h4 id="run-the-program">The freedom to run the program as you wish</h4>
213    
214    <p>
215  The freedom to run the program means the freedom for any kind of person  The freedom to run the program means the freedom for any kind of person
216  or organization to use it on any kind of computer system, for any kind of  or organization to use it on any kind of computer system, for any kind of
217  overall job and purpose, without being required to communicate about it  overall job and purpose, without being required to communicate about it
218  with the developer or any other specific entity.  In this freedom, it is  with the developer or any other specific entity.  In this freedom, it is
219  the <em>user's</em> purpose that matters, not the <em>developer's</em>  the <em>user's</em> purpose that matters, not the <em>developer's</em>
220  purpose; you as a user are free to run a program for your purposes,  purpose; you as a user are free to run the program for your purposes,
221  and if you distribute it to someone else, she is then free to run it  and if you distribute it to someone else, she is then free to run it
222  for her purposes, but you are not entitled to impose your purposes on her.  for her purposes, but you are not entitled to impose your purposes on her.
223  </p>  </p>
224    
225  <p>  <p>
226    The freedom to run the program as you wish means that you are not
227    forbidden or stopped from making it run.  This has nothing to do with what
228    functionality the program has, whether it is technically capable of
229    functioning in any given environment, or whether it is useful for any
230    particular computing activity.</p>
231    
232    <p>For example, if the code arbitrarily rejects certain meaningful
233    inputs&mdash;or even fails unconditionally&mdash;that may make the
234    program less useful, perhaps even totally useless, but it does not
235    deny users the freedom to run the program, so it does not conflict
236    with freedom 0.  If the program is free, the users can overcome the
237    loss of usefulness, because freedoms 1 and 3 permit users and
238    communities to make and distribute modified versions without the
239    arbitrary nuisance code.</p>
240    
241    <p>&ldquo;As you wish&rdquo; includes, optionally, &ldquo;not at
242    all&rdquo; if that is what you wish.  So there is no need for a
243    separate &ldquo;freedom not to run a program.&rdquo;</p>
244    
245    <h4 id="make-changes">The freedom to study the source code and make changes</h4>
246    
247    <p>
248    In order for freedoms 1 and 3 (the freedom to make changes and the
249    freedom to publish the changed versions) to be meaningful, you need to have
250    access to the source code of the program.  Therefore, accessibility of
251    source code is a necessary condition for free software.  Obfuscated
252    &ldquo;source code&rdquo; is not real source code and does not count
253    as source code.
254    </p>
255    
256    <p>
257    Freedom 1 includes the freedom to use your changed version in place of
258    the original.  If the program is delivered in a product designed to
259    run someone else's modified versions but refuse to run yours &mdash; a
260    practice known as &ldquo;tivoization&rdquo; or &ldquo;lockdown&rdquo;,
261    or (in its practitioners' perverse terminology) as &ldquo;secure
262    boot&rdquo; &mdash; freedom 1 becomes an empty pretense rather than a
263    practical reality.  These binaries are not free
264    software even if the source code they are compiled from is free.
265    </p>
266    
267    <p>
268    One important way to modify a program is by merging in available free
269    subroutines and modules.  If the program's license says that you
270    cannot merge in a suitably licensed existing module &mdash; for instance, if it
271    requires you to be the copyright holder of any code you add &mdash; then the
272    license is too restrictive to qualify as free.
273    </p>
274    
275    <p>
276    Whether a change constitutes an improvement is a subjective matter.
277    If your right to modify a program is limited, in substance, to changes that
278    someone else considers an improvement, that program is not free.
279    </p>
280    
281    <p>
282    One special case of freedom 1 is to delete the program's code so it
283    returns after doing nothing, or make it invoke some other program.
284    Thus, freedom 1 includes the &ldquo;freedom to delete the program.&rdquo;
285    </p>
286    
287    <h4 id="redistribute">The freedom to redistribute if you wish: basic
288    requirements</h4>
289    
290    <p>Freedom to distribute (freedoms 2 and 3) means you are free to
291    redistribute copies, either with or without modifications, either
292    gratis or charging a fee for distribution, to
293    <a href="#exportcontrol">anyone anywhere</a>.  Being free to do these
294    things means (among other things) that you do not have to ask or pay
295    for permission to do so.
296    </p>
297    
298    <p>
299    You should also have the freedom to make modifications and use them
300    privately in your own work or play, without even mentioning that they
301    exist.  If you do publish your changes, you should not be required to
302    notify anyone in particular, or in any particular way.
303    </p>
304    
305    <p>
306    Freedom 3 includes the freedom to release your modified versions
307    as free software.  A free license may also permit other ways of
308    releasing them; in other words, it does not have to be
309    a <a href="/licenses/copyleft.html">copyleft</a> license.  However, a
310    license that requires modified versions to be nonfree does not qualify
311    as a free license.
312    </p>
313    
314    <p>
315  The freedom to redistribute copies must include binary or executable  The freedom to redistribute copies must include binary or executable
316  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
317  unmodified versions.  (Distributing programs in runnable form is necessary  unmodified versions.  (Distributing programs in runnable form is necessary
318  for conveniently installable free operating systems.)  It is ok if there  for conveniently installable free operating systems.)  It is OK if there
319  is no way to produce a binary or executable form for a certain program  is no way to produce a binary or executable form for a certain program
320  (since some languages don't support that feature), but you must have the  (since some languages don't support that feature), but you must have the
321  freedom to redistribute such forms should you find or develop a way to  freedom to redistribute such forms should you find or develop a way to
322  make them.  make them.
323  </p>  </p>
324    
325    <h4 id="copyleft">Copyleft</h4>
326    
327  <p>  <p>
328  In order for the freedoms to make changes, and to publish improved  Certain kinds of rules about the manner of distributing free
329  versions, to be meaningful, you must have access to the source code of  software are acceptable, when they don't conflict with the central
330  the program.  Therefore, accessibility of source code is a necessary  freedoms.  For example, <a href="/licenses/copyleft.html">copyleft</a>
331  condition for free software.  (very simply stated) is the rule that when redistributing the program,
332    you cannot add restrictions to deny other people the central freedoms.
333    This rule does not conflict with the central freedoms; rather it
334    protects them.
335  </p>  </p>
336    
337  <p>  <p>
338  One important way to modify a program is by merging in available  In the GNU project, we use copyleft to protect the four freedoms
339  free subroutines and modules.  If the program's license says that you  legally for everyone.  We believe there are important reasons why
340  cannot merge in an existing module, such as if it requires you to be the  <a href="/philosophy/pragmatic.html">it is better to use
341  copyright holder of any code you add, then the license is too restrictive  copyleft</a>.  However,
342  to qualify as free.  <a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">
343    noncopylefted free software</a> is ethical
344    too.  See <a href="/philosophy/categories.html">Categories of Free
345    Software</a> for a description of how &ldquo;free software,&rdquo;
346    &ldquo;copylefted software&rdquo; and other categories of software
347    relate to each other.
348  </p>  </p>
349    
350    <h4 id="packaging">Rules about packaging and distribution details</h4>
351    
352  <p>  <p>
353  In order for these freedoms to be real, they must be irrevocable as  Rules about how to package a modified version are acceptable,
354  long as you do nothing wrong; if the developer of the software has the  if they don't substantively limit your freedom to release modified
355  power to revoke the license, without your doing anything to give cause,  versions, or your freedom to make and use modified versions privately.
356  the software is not free.  Thus, it is acceptable for the license to require that you change the
357    name of the modified version, remove a logo, or identify your
358    modifications as yours.  As long as these requirements are not so
359    burdensome that they effectively hamper you from releasing your
360    changes, they are acceptable; you're already making other changes to
361    the program, so you won't have trouble making a few more.
362  </p>  </p>
363    
364  <p>  <p>
365  However, certain kinds of rules about the manner of distributing free  Rules that &ldquo;if you make your version available in this way, you
366  software are acceptable, when they don't conflict with the central  must make it available in that way also&rdquo; can be acceptable too,
367  freedoms.  For example, copyleft (very simply stated) is the rule that  on the same condition.  An example of such an acceptable rule is one
368  when redistributing the program, you cannot add restrictions to deny  saying that if you have distributed a
369  other people the central freedoms.  This rule does not conflict with  modified version and a previous developer asks for a copy of it, you
370  the central freedoms; rather it protects them.  must send one.  (Note that such a rule still leaves you the choice of
371    whether to distribute your version at all.)  Rules that require release
372    of source code to the users for versions that you put into public use
373    are also acceptable.
374  </p>  </p>
375    
376  <p>  <p>
377  You may have paid money to get copies of free software, or you may have  A special issue arises when a license requires changing the name by
378  obtained copies at no charge.  But regardless of how you got your copies,  which the program will be invoked from other programs.  That
379  you always have the freedom to copy and change the software, even to  effectively hampers you from releasing your changed version so that it
380  <a href="/philosophy/selling.html">sell copies</a>.  can replace the original when invoked by those other programs.  This
381  </p>  sort of requirement is acceptable only if there's a suitable aliasing
382    facility that allows you to specify the original program's name as an
383    alias for the modified version.</p>
384    
385    <h4 id="exportcontrol">Export regulations</h4>
386    
387  <p>  <p>
388  <q>Free software</q> does not mean <q>non-commercial.</q>  A free  Sometimes government export control regulations
389  program must be available for commercial use, commercial development,  and trade sanctions can constrain your freedom to distribute copies of
390  and commercial distribution.  Commercial development of free software  programs internationally.  Software developers do not have the power to
391  is no longer unusual; such free commercial software is very important.  eliminate or override these restrictions, but what they can and must do
392    is refuse to impose them as conditions of use of the program.  In this
393    way, the restrictions will not affect activities and people outside the
394    jurisdictions of these governments.  Thus, free software licenses
395    must not require obedience to any nontrivial export regulations as a
396    condition of exercising any of the essential freedoms.
397  </p>  </p>
398    
399  <p>  <p>
400  Rules about how to package a modified version are acceptable, if they  Merely mentioning the existence of export regulations, without making
401  don't substantively block your freedom to release modified versions, or  them a condition of the license itself, is acceptable since it does
402  your freedom to make and use modified versions privately.  Rules that <q>if  not restrict users.  If an export regulation is actually trivial for
403  you make your version available in this way, you must make it available in  free software, then requiring it as a condition is not an actual
404  that way also</q> can be acceptable too, on the same condition.  (Note that  problem; however, it is a potential problem, since a later change in
405  such a rule still leaves you the choice of whether to publish your version  export law could make the requirement nontrivial and thus render the
406  at all.)  Rules that require release of source code to the users for  software nonfree.
 versions that you put into public use are also acceptable.  It is also  
 acceptable for the license to require that, if you have distributed a  
 modified version and a previous developer asks for a copy of it, you  
 must send one, or that you identify yourself on your modifications.  
407  </p>  </p>
408    
409    <h4 id="legal-details">Legal considerations</h4>
410    
411  <p>  <p>
412  In the GNU project, we use  In order for these freedoms to be real, they must be permanent and
413  <q><a href="/copyleft/copyleft.html">copyleft</a></q>  irrevocable as long as you do nothing wrong; if the developer of the
414  to protect these freedoms legally for everyone.  But  software has the power to revoke the license, or retroactively add
415  <a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">non-copylefted  restrictions to its terms, without your doing anything wrong to give
416  free software</a> also exists.  We believe there are important reasons why  cause, the software is not free.
 <a href="/philosophy/pragmatic.html"> it is better to use copyleft</a>,  
 but if your program is non-copylefted free software, we can still  
 use it.  
417  </p>  </p>
418    
419  <p>  <p>
420  See <a href="/philosophy/categories.html">Categories of Free Software</a>  A free license may not require compliance with the license of a
421  for a description of how <q>free software,</q> <q>copylefted software</q>  nonfree program.  Thus, for instance, if a license requires you to
422  and other categories of software relate to each other.  comply with the licenses of &ldquo;all the programs you use&rdquo;, in
423    the case of a user that runs nonfree programs this would require
424    compliance with the licenses of those nonfree programs; that makes the
425    license nonfree.
426  </p>  </p>
427    
428  <p>  <p>
429  Sometimes government <a id="exportcontrol">export control regulations</a>  It is acceptable for a free license to specify which jurisdiction's
430  and trade sanctions can constrain your freedom to distribute copies of  law applies, or where litigation must be done, or both.
 programs internationally.  Software developers do not have the power to  
 eliminate or override these restrictions, but what they can and must do  
 is refuse to impose them as conditions of use of the program.  In this  
 way, the restrictions will not affect activities and people outside the  
 jurisdictions of these governments.  
431  </p>  </p>
432    
433    <h4 id="contracts">Contract-based licenses</h4>
434    
435  <p>  <p>
436  Most free software licenses are based on copyright, and there are limits  Most free software licenses are based on copyright, and there are limits
437  on what kinds of requirements can be imposed through copyright.  If a  on what kinds of requirements can be imposed through copyright.  If a
# Line 176  is unlikely to have some other sort of p Line 440  is unlikely to have some other sort of p
440  (though this does happen occasionally).  However, some free software  (though this does happen occasionally).  However, some free software
441  licenses are based on contracts, and contracts can impose a much larger  licenses are based on contracts, and contracts can impose a much larger
442  range of possible restrictions.  That means there are many possible ways  range of possible restrictions.  That means there are many possible ways
443  such a license could be unacceptably restrictive and non-free.  such a license could be unacceptably restrictive and nonfree.
444  </p>  </p>
445    
446  <p>  <p>
# Line 184  We can't possibly list all the ways that Line 448  We can't possibly list all the ways that
448  contract-based license restricts the user in an unusual way that  contract-based license restricts the user in an unusual way that
449  copyright-based licenses cannot, and which isn't mentioned here as  copyright-based licenses cannot, and which isn't mentioned here as
450  legitimate, we will have to think about it, and we will probably conclude  legitimate, we will have to think about it, and we will probably conclude
451  it is non-free.  it is nonfree.
452  </p>  </p>
453    
454  <p>  <h3 id="in-practice" class="subheader">The Free Software Definition in Practice</h3>
455  When talking about free software, it is best to avoid using terms  
456  like <q>give away</q> or <q>for free,</q> because those terms imply that  <h4 id="interpretation">How we interpret these criteria</h4>
 the issue is about price, not freedom.  Some common terms such  
 as <q>piracy</q> embody opinions we hope you won't endorse.  See  
 <a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases that  
 are Worth Avoiding</a> for a discussion of these terms.  We also have  
 a list of <a href="/philosophy/fs-translations.html">translations of  
 <q>free software</q></a> into various languages.  
 </p>  
457    
458  <p>  <p>
459  Finally, note that criteria such as those stated in this free software  Note that criteria such as those stated in this free software
460  definition require careful thought for their interpretation.  To decide  definition require careful thought for their interpretation.  To decide
461  whether a specific software license qualifies as a free software license,  whether a specific software license qualifies as a free software license,
462  we judge it based on these criteria to determine whether it fits their  we judge it based on these criteria to determine whether it fits their
# Line 212  a conclusion about a new issue, we often Line 469  a conclusion about a new issue, we often
469  it easier to see why certain licenses do or don't qualify.  it easier to see why certain licenses do or don't qualify.
470  </p>  </p>
471    
472    <h4 id="get-help">Get help with free licenses</h4>
473    
474  <p>  <p>
475  If you are interested in whether a specific license qualifies as a free  If you are interested in whether a specific license qualifies as a free
476  software license, see our <a href="/licenses/license-list.html">list  software license, see our <a href="/licenses/license-list.html">list
# Line 221  listed there, you can ask us about it by Line 480  listed there, you can ask us about it by
480  </p>  </p>
481    
482  <p>  <p>
483  If you are contemplating writing a new license, please contact the FSF  If you are contemplating writing a new license, please contact the
484  by writing to that address. The proliferation of different free software  Free Software Foundation first by writing to that address. The
485  licenses means increased work for users in understanding the licenses;  proliferation of different free software licenses means increased work
486  we may be able to help you find an existing Free Software license that  for users in understanding the licenses; we may be able to help you
487  meets your needs.  find an existing free software license that meets your needs.
488  </p>  </p>
489    
490  <p>  <p>
491  If that isn't possible, if you really need a new license, with our  If that isn't possible, if you really need a new license, with our
492  help you can ensure that the license really is a Free Software license  help you can ensure that the license really is a free software license
493  and avoid various practical problems.  and avoid various practical problems.
494  </p>  </p>
495    
496  <h2 id="open-source">Open Source?</h2>  <h4 id="terminology">Use the right words when talking about free software</h4>
497    
498  <p>  <p>
499  Another group has started using the term <q>open source</q> to mean  When talking about free software, it is best to avoid using terms
500  something close (but not identical) to <q>free software.</q>  We prefer  like &ldquo;give away&rdquo; or &ldquo;for free,&rdquo; because those terms imply that
501  the term <q>free software</q> because, once you have heard it refers to  the issue is about price, not freedom.  Some common terms such
502  freedom rather than price, <a href="free-software-for-freedom.html">it  as &ldquo;piracy&rdquo; embody opinions we hope you won't endorse.  See
503  calls to mind freedom</a>.  The word <q>open</q> never does that.  <a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases that
504    are Worth Avoiding</a> for a discussion of these terms.  We also have
505    a list of proper <a href="/philosophy/fs-translations.html">translations of
506    &ldquo;free software&rdquo;</a> into various languages.
507  </p>  </p>
508    
509  <p><a href="/philosophy/philosophy.html">Other Texts to Read</a></p>  <p id="open-source">
510    Another group uses the term &ldquo;open source&rdquo; to mean
511  </div>  something close (but not identical) to &ldquo;free software&rdquo;.  We
512    prefer the term &ldquo;free software&rdquo; because, once you have heard that
513    it refers to freedom rather than price, it calls to mind freedom.  The
514  <!--#include virtual="/server/footer.html" -->  word &ldquo;open&rdquo; never refers to freedom.
   
 <div id="footer">  
   
 <p>  
 Please send FSF &amp; GNU inquiries to  
 <a href="mailto:gnu@gnu.org"><em>gnu@gnu.org</em></a>.  
 There are also <a href="http://www.fsf.org/about/contact.html">other ways to contact</a>  
 the FSF.  
 <br />  
 Please send broken links and other corrections (or suggestions) to  
 <a href="mailto:webmasters@gnu.org"><em>webmasters@gnu.org</em></a>.  
515  </p>  </p>
516    
517    <h3 id="beyond-software" class="subheader">Beyond Software</h3>
518    
519  <p>  <p>
520  Please see the  <a href="/philosophy/free-doc.html">Software manuals must be free</a>,
521  <a href="/server/standards/README.translations.html">Translations  for the same reasons that software must be free, and because the
522  README</a> for information on coordinating and submitting  manuals are in effect part of the software.
 translations of this article.  
523  </p>  </p>
524    
525  <p>  <p>
526  Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,  The same arguments also make sense for other kinds of works of
527  2005, 2006 <br /> Free Software Foundation, Inc., 51 Franklin St,  practical use &mdash; that is to say, works that embody useful knowledge,
528  Fifth Floor, Boston, MA 02110-1301,  USA  such as educational works and reference
529  <br />  works.  <a href="https://wikipedia.org">Wikipedia</a> is the best-known
530  Verbatim copying and distribution of this entire article is  example.
 permitted in any medium without royalty provided this notice is  
 preserved.  
531  </p>  </p>
532    
533  <p>  <p>
534  Updated:  Any kind of work <em>can</em> be free, and the definition of free software
535  <!-- timestamp start -->  has been extended to a definition of <a href="http://freedomdefined.org/">
536  $Date$ $Author$  free cultural works</a> applicable to any kind of works.
 <!-- timestamp end -->  
537  </p>  </p>
538    <hr class="column-limit" />
539  </div>  </div>
540    
541  <div id="translations">  <h3 id="History">History</h3>
542  <h4>Translations of this page</h4>  
543    <p>From time to time we revise this Free Software Definition.  Here is
544    the list of substantive changes, along with links to show exactly what
545    was changed.</p>
546    
547    <ul>
548    
549    <li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;r1=1.168&amp;r2=1.169">Version
550    1.169</a>: Explain more clearly why the four freedoms must apply
551    to commercial activity.  Explain why the four freedoms imply the
552    freedom not to run the program and the freedom to delete it, so there
553    is no need to state those as separate requirements.</li>
554    
555    <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
556    1.165</a>: Clarify that arbitrary annoyances in the code do not
557    negate freedom 0, and that freedoms 1 and 3 enable users to remove them.</li>
558    
559    <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
560    1.153</a>: Clarify that freedom to run the program means nothing stops
561    you from making it run.</li>
562    
563    <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
564    1.141</a>: Clarify which code needs to be free.</li>
565    
566    <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
567    1.135</a>: Say each time that freedom 0 is the freedom to run the program
568    as you wish.</li>
569    
570    <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
571    1.134</a>: Freedom 0 is not a matter of the program's functionality.</li>
572    
573    <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
574    1.131</a>: A free license may not require compliance with a nonfree license
575    of another program.</li>
576    
577    <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
578    1.129</a>: State explicitly that choice of law and choice of forum
579    specifications are allowed.  (This was always our policy.)</li>
580    
581    <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
582    1.122</a>: An export control requirement is a real problem if the
583    requirement is nontrivial; otherwise it is only a potential problem.</li>
584    
585    <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
586    1.118</a>: Clarification: the issue is limits on your right to modify,
587    not on what modifications you have made.  And modifications are not limited
588    to &ldquo;improvements&rdquo;</li>
589    
590    <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
591    1.111</a>: Clarify 1.77 by saying that only
592    retroactive <em>restrictions</em> are unacceptable.  The copyright
593    holders can always grant additional <em>permission</em> for use of the
594    work by releasing the work in another way in parallel.</li>
595    
596    <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
597    1.105</a>: Reflect, in the brief statement of freedom 1, the point
598    (already stated in version 1.80) that it includes really using your modified
599    version for your computing.</li>
600    
601    <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
602    1.92</a>: Clarify that obfuscated code does not qualify as source code.</li>
603    
604    <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
605    1.90</a>: Clarify that freedom 3 means the right to distribute copies
606    of your own modified or improved version, not a right to participate
607    in someone else's development project.</li>
608    
609    <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
610    1.89</a>: Freedom 3 includes the right to release modified versions as
611    free software.</li>
612    
613    <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
614    1.80</a>: Freedom 1 must be practical, not just theoretical;
615    i.e., no tivoization.</li>
616    
617    <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
618    1.77</a>: Clarify that all retroactive changes to the license are
619    unacceptable, even if it's not described as a complete
620    replacement.</li>
621    
622    <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
623    1.74</a>: Four clarifications of points not explicit enough, or stated
624    in some places but not reflected everywhere:
625    <ul>
626    <li>"Improvements" does not mean the license can
627    substantively limit what kinds of modified versions you can release.
628    Freedom 3 includes distributing modified versions, not just changes.</li>
629    <li>The right to merge in existing modules
630    refers to those that are suitably licensed.</li>
631    <li>Explicitly state the conclusion of the point about export controls.</li>
632    <li>Imposing a license change constitutes revoking the old license.</li>
633    </ul>
634    </li>
635    
636    <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
637    1.57</a>: Add &quot;Beyond Software&quot; section.</li>
638    
639    <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
640    1.46</a>: Clarify whose purpose is significant in the freedom to run
641    the program for any purpose.</li>
642    
643    <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
644    1.41</a>: Clarify wording about contract-based licenses.</li>
645    
646    <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
647    1.40</a>: Explain that a free license must allow to you use other
648    available free software to create your modifications.</li>
649    
650    <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
651    1.39</a>: Note that it is acceptable for a license to require you to
652    provide source for versions of the software you put into public
653    use.</li>
654    
655    <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
656    1.31</a>: Note that it is acceptable for a license to require you to
657    identify yourself as the author of modifications.  Other minor
658    clarifications throughout the text.</li>
659    
660    <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
661    1.23</a>: Address potential problems related to contract-based
662    licenses.</li>
663    
664    <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
665    1.16</a>: Explain why distribution of binaries is important.</li>
666    
667    <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
668    1.11</a>: Note that a free license may require you to send a copy of
669    versions you distribute to previous developers on request.</li>
670    
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  <li><a href="/philosophy/free-sw.nl.html">Nederlands</a>       <!-- Dutch --></li>  
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  <li><a href="/philosophy/free-sw.sl.html">Slovinsko</a>        <!--- Slovenian --></li>  
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  <li><a href="/philosophy/free-sw.tl.html">Tagalog</a>  <!-- Tagalog --></li>  
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671  </ul>  </ul>
672    
673    <p>There are gaps in the version numbers shown above because there are
674    other changes in this page that do not affect the definition or its
675    interpretations.  For instance, the list does not include changes in
676    asides, formatting, spelling, punctuation, or other parts of the page.
677    You can review the complete list of changes to the page through
678    the <a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;view=log">cvsweb
679    interface</a>.</p>
680    <hr class="column-limit" />
681    
682    <h3 class="footnote">Footnote</h3>
683    <ol>
684    <li id="f1">The reason they are numbered 0, 1, 2 and 3 is historical. Around
685    1990 there were three freedoms, numbered 1, 2 and 3. Then we realized that
686    the freedom to run the program needed to be mentioned explicitly.
687    It was clearly more basic than the other three, so it properly should
688    precede them. Rather than renumber the others, we made it freedom&nbsp;0.</li>
689    </ol>
690  </div>  </div>
691    
692    </div><!-- for id="content", starts in the include above -->
693    <!--#include virtual="/server/footer.html" -->
694    <div id="footer" role="contentinfo">
695    <div class="unprintable">
696    
697    <p>Please send general FSF &amp; GNU inquiries to
698    <a href="mailto:gnu@gnu.org">&lt;gnu@gnu.org&gt;</a>.
699    There are also <a href="/contact/">other ways to contact</a>
700    the FSF.  Broken links and other corrections or suggestions can be sent
701    to <a href="mailto:webmasters@gnu.org">&lt;webmasters@gnu.org&gt;</a>.</p>
702    
703    <p><!-- TRANSLATORS: Ignore the original text in this paragraph,
704            replace it with the translation of these two:
705    
706            We work hard and do our best to provide accurate, good quality
707            translations.  However, we are not exempt from imperfection.
708            Please send your comments and general suggestions in this regard
709            to <a href="mailto:web-translators@gnu.org">
710            &lt;web-translators@gnu.org&gt;</a>.</p>
711    
712            <p>For information on coordinating and contributing translations of
713            our web pages, see <a
714            href="/server/standards/README.translations.html">Translations
715            README</a>. -->
716    Please see the <a
717    href="/server/standards/README.translations.html">Translations
718    README</a> for information on coordinating and contributing translations
719    of this article.</p>
720  </div>  </div>
721    
722    <!-- Regarding copyright, in general, standalone pages (as opposed to
723         files generated as part of manuals) on the GNU web server should
724         be under CC BY-ND 4.0.  Please do NOT change or remove this
725         without talking with the webmasters or licensing team first.
726         Please make sure the copyright date is consistent with the
727         document.  For web pages, it is ok to list just the latest year the
728         document was modified, or published.
729        
730         If you wish to list earlier years, that is ok too.
731         Either "2001, 2002, 2003" or "2001-2003" are ok for specifying
732         years, as long as each year in the range is in fact a copyrightable
733         year, i.e., a year in which the document was published (including
734         being publicly visible on the web or in a revision control system).
735        
736         There is more detail about copyright years in the GNU Maintainers
737         Information document, www.gnu.org/prep/maintain. -->
738    
739    <p>Copyright &copy; 1996-2002, 2004-2007, 2009-2019, 2021
740    Free Software Foundation, Inc.</p>
741    
742    <p>This page is licensed under a <a rel="license"
743    href="http://creativecommons.org/licenses/by-nd/4.0/">Creative
744    Commons Attribution-NoDerivatives 4.0 International License</a>.</p>
745    
746    <!--#include virtual="/server/bottom-notes.html" -->
747    
748    <p class="unprintable">Updated:
749    <!-- timestamp start -->
750    $Date$
751    <!-- timestamp end -->
752    </p>
753    </div>
754    </div><!-- for class="inner", starts in the banner include -->
755  </body>  </body>
756  </html>  </html>

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