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1  <!--#include virtual="/server/header.html" -->  <!--#include virtual="/server/header.html" -->
2    <!-- Parent-Version: 1.77 -->
3  <title>What is free software? - GNU Project - Free Software Foundation (FSF)</title>  <title>What is free software?
4    - GNU Project - Free Software Foundation</title>
5    
6  <meta http-equiv="Keywords" content="GNU, FSF, Free Software Foundation, Linux, Emacs, GCC, Unix, Free Software, Operating System, GNU Kernel, HURD, GNU HURD, Hurd" />  <meta http-equiv="Keywords" content="GNU, FSF, Free Software Foundation, Linux, Emacs, GCC, Unix, Free Software, Operating System, GNU Kernel, HURD, GNU HURD, Hurd" />
7  <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." />  <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." />
 <link rel="alternate" title="What's New" href="http://www.gnu.org/rss/whatsnew.rss" type="application/rss+xml" />  
 <link rel="alternate" title="New Free Software" href="http://www.gnu.org/rss/quagga.rss" type="application/rss+xml" />  
8    
9  <!--#include virtual="/philosophy/po/free-sw.translist" -->  <!--#include virtual="/philosophy/po/free-sw.translist" -->
10  <!--#include virtual="/server/banner.html" -->  <!--#include virtual="/server/banner.html" -->
11    
12  <h2>What is free software?</h2>  <h2>What is free software?</h2>
13    <!--#include virtual="/licenses/fsf-licensing.html" -->
14    
15  <h3>The Free Software Definition</h3>  <h3>The Free Software Definition</h3>
16    
# Line 27  software. Line 27  software.
27    
28  <p>  <p>
29  &ldquo;Free software&rdquo; means software that respects users'  &ldquo;Free software&rdquo; means software that respects users'
30  freedom and community.  Roughly, <b>the users have the freedom to run,  freedom and community.  Roughly, it means that <b>the users have the
31  copy, distribute, study, change and improve the software</b>.  With these  freedom to run, copy, distribute, study, change and improve the
32  freedoms, the users (both individually and collectively) control the  software</b>.  Thus, &ldquo;free software&rdquo; is a matter of
33  program and what it does for them.  liberty, not price.  To understand the concept, you should think of
34    &ldquo;free&rdquo; as in &ldquo;free speech,&rdquo; not as in
35    &ldquo;free beer&rdquo;.  We sometimes call it &ldquo;libre
36    software,&rdquo; borrowing the French or Spanish word for
37    &ldquo;free&rdquo; as in freedom, to show we do not mean the software
38    is gratis.
39  </p>  </p>
40    
41  <p>  <p>
42  When users don't control the program, the program controls the users.  We campaign for these freedoms because everyone deserves them.  With
43  The developer controls the program, and through it controls the users.  these freedoms, the users (both individually and collectively) control
44  This nonfree or &ldquo;proprietary&rdquo; program is therefore an  the program and what it does for them.  When users don't control the
45  instrument of unjust power.  program, we call it a &ldquo;nonfree&rdquo; or
46  </p>  &ldquo;proprietary&rdquo; program.  The nonfree program controls the
47    users, and the developer controls the program; this makes the
48  <p>  program <a href="/philosophy/free-software-even-more-important.html">
49  Thus, &ldquo;free software&rdquo; is a matter of liberty, not price.  an instrument of unjust power</a>.
 To understand the concept, you should think of &ldquo;free&rdquo; as  
 in &ldquo;free speech,&rdquo; not as in &ldquo;free beer&rdquo;.  
50  </p>  </p>
51    
52  <p>  <p>
# Line 52  four essential freedoms: Line 55  four essential freedoms:
55  </p>  </p>
56    
57  <ul>  <ul>
58    <li>The freedom to run the program, for any purpose (freedom 0).</li>    <li>The freedom to run the program as you wish,
59          for any purpose (freedom 0).</li>
60    <li>The freedom to study how the program works, and change it so it    <li>The freedom to study how the program works, and change it so it
61        does your computing as you wish (freedom 1). Access to the source        does your computing as you wish (freedom 1). Access to the source
62        code is a precondition for this.        code is a precondition for this.
# Line 68  four essential freedoms: Line 72  four essential freedoms:
72  </ul>  </ul>
73    
74  <p>  <p>
75  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
76  you should be free to redistribute copies, either with or without  freedoms.  Otherwise, it is nonfree.  While we can distinguish various
77  modifications, either gratis or charging a fee for distribution, to  nonfree distribution schemes in terms of how far they fall short of
78    being free, we consider them all equally unethical.</p>
79    
80    <p>In any given scenario, these freedoms must apply to whatever code
81    we plan to make use of, or lead others to make use of.  For instance,
82    consider a program A which automatically launches a program B to
83    handle some cases.  If we plan to distribute A as it stands, that
84    implies users will need B, so we need to judge whether both A and B
85    are free.  However, if we plan to modify A so that it doesn't use B,
86    only A needs to be free; B is not pertinent to that plan.</p>
87    
88    <p>The rest of this page clarifies certain points about what makes
89    specific freedoms adequate or not.</p>
90    
91    <p>Freedom to distribute (freedoms 2 and 3) means you are free to
92    redistribute copies, either with or without modifications, either
93    gratis or charging a fee for distribution, to
94  <a href="#exportcontrol">anyone anywhere</a>.  Being free to do these  <a href="#exportcontrol">anyone anywhere</a>.  Being free to do these
95  things means (among other things) that you do not have to ask or pay  things means (among other things) that you do not have to ask or pay
96  for permission to do so.  for permission to do so.
# Line 95  for her purposes, but you are not entitl Line 115  for her purposes, but you are not entitl
115  </p>  </p>
116    
117  <p>  <p>
118    The freedom to run the program as you wish means that you are not
119    forbidden or stopped from doing so.  It has nothing to do with what
120    functionality the program has, or whether it is useful for what you
121    want to do.</p>
122    
123    <p>
124  The freedom to redistribute copies must include binary or executable  The freedom to redistribute copies must include binary or executable
125  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
126  unmodified versions.  (Distributing programs in runnable form is necessary  unmodified versions.  (Distributing programs in runnable form is necessary
# Line 120  the original.  If the program is deliver Line 146  the original.  If the program is deliver
146  run someone else's modified versions but refuse to run yours &mdash; a  run someone else's modified versions but refuse to run yours &mdash; a
147  practice known as &ldquo;tivoization&rdquo; or &ldquo;lockdown&rdquo;,  practice known as &ldquo;tivoization&rdquo; or &ldquo;lockdown&rdquo;,
148  or (in its practitioners' perverse terminology) as &ldquo;secure  or (in its practitioners' perverse terminology) as &ldquo;secure
149  boot&rdquo; &mdash; freedom 1 becomes a theoretical fiction rather  boot&rdquo; &mdash; freedom 1 becomes an empty pretense rather than a
150  than a practical freedom.  This is not sufficient.  In other words,  practical reality.  These binaries are not free
151  these binaries are not free software even if the source code they are  software even if the source code they are compiled from is free.
 compiled from is free.  
152  </p>  </p>
153    
154  <p>  <p>
# Line 154  cause, the software is not free. Line 179  cause, the software is not free.
179  <p>  <p>
180  However, certain kinds of rules about the manner of distributing free  However, certain kinds of rules about the manner of distributing free
181  software are acceptable, when they don't conflict with the central  software are acceptable, when they don't conflict with the central
182  freedoms.  For example, copyleft (very simply stated) is the rule that  freedoms.  For example, <a href="/copyleft/copyleft.html">copyleft</a>
183  when redistributing the program, you cannot add restrictions to deny  (very simply stated) is the rule that when redistributing the program,
184  other people the central freedoms.  This rule does not conflict with  you cannot add restrictions to deny other people the central freedoms.
185  the central freedoms; rather it protects them.  This rule does not conflict with the central freedoms; rather it
186    protects them.
187    </p>
188    
189    <p>
190    In the GNU project, we use copyleft to protect the four freedoms
191    legally for everyone.  We believe there are important reasons why
192    <a href="/philosophy/pragmatic.html">it is better to use
193    copyleft</a>.  However,
194    <a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">
195    noncopylefted free software</a> is ethical
196    too.  See <a href="/philosophy/categories.html">Categories of Free
197    Software</a> for a description of how &ldquo;free software,&rdquo;
198    &ldquo;copylefted software&rdquo; and other categories of software
199    relate to each other.
200  </p>  </p>
201    
202  <p>  <p>
# Line 211  facility that allows you to specify the Line 250  facility that allows you to specify the
250  alias for the modified version.</p>  alias for the modified version.</p>
251    
252  <p>  <p>
 In the GNU project, we use  
 <a href="/copyleft/copyleft.html">copyleft</a>  
 to protect these freedoms legally for everyone.  But  
 <a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">noncopylefted  
 free software</a> also exists.  We believe there are important reasons why  
 <a href="/philosophy/pragmatic.html">it is better to use copyleft</a>,  
 but if your program is noncopylefted free software, it is still basically  
 ethical. (See <a href="/philosophy/categories.html">Categories of Free Software</a> for a description of how &ldquo;free software,&rdquo; &ldquo;copylefted software&rdquo; and other categories of software relate to each other.)  
 </p>  
   
 <p>  
253  Sometimes government <a id="exportcontrol">export control regulations</a>  Sometimes government <a id="exportcontrol">export control regulations</a>
254  and trade sanctions can constrain your freedom to distribute copies of  and trade sanctions can constrain your freedom to distribute copies of
255  programs internationally.  Software developers do not have the power to  programs internationally.  Software developers do not have the power to
# Line 229  eliminate or override these restrictions Line 257  eliminate or override these restrictions
257  is refuse to impose them as conditions of use of the program.  In this  is refuse to impose them as conditions of use of the program.  In this
258  way, the restrictions will not affect activities and people outside the  way, the restrictions will not affect activities and people outside the
259  jurisdictions of these governments.  Thus, free software licenses  jurisdictions of these governments.  Thus, free software licenses
260  must not require obedience to any export regulations as a condition of  must not require obedience to any nontrivial export regulations as a
261  any of the essential freedoms.  condition of exercising any of the essential freedoms.
262    </p>
263    
264    <p>
265    Merely mentioning the existence of export regulations, without making
266    them a condition of the license itself, is acceptable since it does
267    not restrict users.  If an export regulation is actually trivial for
268    free software, then requiring it as a condition is not an actual
269    problem; however, it is a potential problem, since a later change in
270    export law could make the requirement nontrivial and thus render the
271    software nonfree.
272    </p>
273    
274    <p>
275    A free license may not require compliance with the license of a
276    nonfree program.  Thus, for instance, if a license requires you to
277    comply with the licenses of &ldquo;all the programs you use&rdquo;, in
278    the case of a user that runs nonfree programs this would require
279    compliance with the licenses of those nonfree programs; that makes the
280    license nonfree.
281    </p>
282    
283    <p>
284    It is acceptable for a free license to specify which jurisdiction's
285    law applies, or where litigation must be done, or both.
286  </p>  </p>
287    
288  <p>  <p>
# Line 324  free cultural works</a> applicable to an Line 376  free cultural works</a> applicable to an
376  <h3 id="open-source">Open Source?</h3>  <h3 id="open-source">Open Source?</h3>
377    
378  <p>  <p>
379  Another group has started using the term &ldquo;open source&rdquo; to mean  Another group uses the term &ldquo;open source&rdquo; to mean
380  something close (but not identical) to &ldquo;free software&rdquo;.  We  something close (but not identical) to &ldquo;free software&rdquo;.  We
381  prefer the term &ldquo;free software&rdquo; because, once you have heard that  prefer the term &ldquo;free software&rdquo; because, once you have heard that
382  it refers to freedom rather than price, it calls to mind freedom.  The  it refers to freedom rather than price, it calls to mind freedom.  The
# Line 340  was changed.</p> Line 392  was changed.</p>
392    
393  <ul>  <ul>
394    
395    <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
396    1.141</a>: Clarify which code needs to be free.</li>
397    
398    <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
399    1.135</a>: Say each time that freedom 0 is the freedom to run the program
400    as you wish.</li>
401    
402    <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
403    1.134</a>: Freedom 0 is not a matter of the program's functionality.</li>
404    
405    <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
406    1.131</a>: A free license may not require compliance with a nonfree license
407    of another program.</li>
408    
409    <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
410    1.129</a>: State explicitly that choice of law and choice of forum
411    specifications are allowed.  (This was always our policy.)</li>
412    
413    <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
414    1.122</a>: An export control requirement is a real problem if the
415    requirement is nontrivial; otherwise it is only a potential problem.</li>
416    
417    <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
418    1.118</a>: Clarification: the issue is limits on your right to modify,
419    not on what modifications you have made.  And modifications are not limited
420    to &ldquo;improvements&rdquo;</li>
421    
422  <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  <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
423  1.111</a>: Clarify 1.77 by saying that only  1.111</a>: Clarify 1.77 by saying that only
424  retroactive <em>restrictions</em> are unacceptable.  The copyright  retroactive <em>restrictions</em> are unacceptable.  The copyright
# Line 419  licenses.</li> Line 498  licenses.</li>
498    
499  <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  <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
500  1.11</a>: Note that a free license may require you to send a copy of  1.11</a>: Note that a free license may require you to send a copy of
501  versions you distribute to the author.</li>  versions you distribute to previous developers on request.</li>
502    
503  </ul>  </ul>
504    
505  <p>There are gaps in the version numbers shown above because there are  <p>There are gaps in the version numbers shown above because there are
506  other changes in this page that do not affect the definition as such.  other changes in this page that do not affect the definition or its
507  These changes are in other parts of the page.  You can review the  interpretations.  For instance, the list does not include changes in
508  complete list of changes to the page through  asides, formatting, spelling, punctuation, or other parts of the page.
509    You can review the complete list of changes to the page through
510  the <a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;view=log">cvsweb  the <a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&amp;view=log">cvsweb
511  interface</a>.</p>  interface</a>.</p>
512    
 </div>  
513    
514    </div><!-- for id="content", starts in the include above -->
515  <!--#include virtual="/server/footer.html" -->  <!--#include virtual="/server/footer.html" -->
   
516  <div id="footer">  <div id="footer">
517    <div class="unprintable">
518    
519  <p>  <p>Please send general FSF &amp; GNU inquiries to
 Please send FSF &amp; GNU inquiries to  
520  <a href="mailto:gnu@gnu.org">&lt;gnu@gnu.org&gt;</a>.  <a href="mailto:gnu@gnu.org">&lt;gnu@gnu.org&gt;</a>.
521  There are also <a href="/contact/">other ways to contact</a>  There are also <a href="/contact/">other ways to contact</a>
522  the FSF.  the FSF.  Broken links and other corrections or suggestions can be sent
523  <br />  to <a href="mailto:webmasters@gnu.org">&lt;webmasters@gnu.org&gt;</a>.</p>
524  Please send broken links and other corrections or suggestions to  
525  <a href="mailto:webmasters@gnu.org">&lt;webmasters@gnu.org&gt;</a>.  <p><!-- TRANSLATORS: Ignore the original text in this paragraph,
526  </p>          replace it with the translation of these two:
527    
528            We work hard and do our best to provide accurate, good quality
529            translations.  However, we are not exempt from imperfection.
530            Please send your comments and general suggestions in this regard
531            to <a href="mailto:web-translators@gnu.org">
532            &lt;web-translators@gnu.org&gt;</a>.</p>
533    
534            <p>For information on coordinating and submitting translations of
535            our web pages, see <a
536            href="/server/standards/README.translations.html">Translations
537            README</a>. -->
538    Please see the <a
539    href="/server/standards/README.translations.html">Translations
540    README</a> for information on coordinating and submitting translations
541    of this article.</p>
542    </div>
543    
544  <p>  <!-- Regarding copyright, in general, standalone pages (as opposed to
545  Please see the       files generated as part of manuals) on the GNU web server should
546  <a href="/server/standards/README.translations.html">Translations       be under CC BY-ND 4.0.  Please do NOT change or remove this
547  README</a> for information on coordinating and submitting       without talking with the webmasters or licensing team first.
548  translations of this article.       Please make sure the copyright date is consistent with the
549  </p>       document.  For web pages, it is ok to list just the latest year the
550         document was modified, or published.
551        
552         If you wish to list earlier years, that is ok too.
553         Either "2001, 2002, 2003" or "2001-2003" are ok for specifying
554         years, as long as each year in the range is in fact a copyrightable
555         year, i.e., a year in which the document was published (including
556         being publicly visible on the web or in a revision control system).
557        
558         There is more detail about copyright years in the GNU Maintainers
559         Information document, www.gnu.org/prep/maintain. -->
560    
561    <p>Copyright &copy; 1996, 2002, 2004-2007, 2009-2016
562    Free Software Foundation, Inc.</p>
563    
 <p>  
 Copyright &copy; 1996-2002, 2004-2007, 2009, 2010, 2012 Free Software  
 Foundation, Inc.  
 </p>  
564  <p>This page is licensed under a <a rel="license"  <p>This page is licensed under a <a rel="license"
565  href="http://creativecommons.org/licenses/by-nd/3.0/us/">Creative  href="http://creativecommons.org/licenses/by-nd/4.0/">Creative
566  Commons Attribution-NoDerivs 3.0 United States License</a>.  Commons Attribution-NoDerivatives 4.0 International License</a>.</p>
 </p>  
567    
568  <!--#include virtual="/server/bottom-notes.html" -->  <!--#include virtual="/server/bottom-notes.html" -->
569    
570  <p>Updated:  <p class="unprintable">Updated:
571  <!-- timestamp start -->  <!-- timestamp start -->
572  $Date$  $Date$
573  <!-- timestamp end -->  <!-- timestamp end -->
574  </p>  </p>
575  </div>  </div>
   
   
576  </div>  </div>
   
577  </body>  </body>
578  </html>  </html>

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