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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; to show we do not mean it is gratis.
37  </p>  </p>
38    
39  <p>  <p>
40  When users don't control the program, the program controls the users.  We campaign for these freedoms because everyone deserves them.  With
41  The developer controls the program, and through it controls the users.  these freedoms, the users (both individually and collectively) control
42  This nonfree or &ldquo;proprietary&rdquo; program is therefore an  the program and what it does for them.  When users don't control the
43  instrument of unjust power.  program, we call it a &ldquo;nonfree&rdquo; or
44  </p>  &ldquo;proprietary&rdquo; program.  The nonfree program controls the
45    users, and the developer controls the program; this makes the
46  <p>  program <a href="/philosophy/free-software-even-more-important.html">
47  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;.  
48  </p>  </p>
49    
50  <p>  <p>
# Line 52  four essential freedoms: Line 53  four essential freedoms:
53  </p>  </p>
54    
55  <ul>  <ul>
56    <li>The freedom to run the program, for any purpose (freedom 0).</li>    <li>The freedom to run the program as you wish,
57          for any purpose (freedom 0).</li>
58    <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
59        does your computing as you wish (freedom 1). Access to the source        does your computing as you wish (freedom 1). Access to the source
60        code is a precondition for this.        code is a precondition for this.
# Line 68  four essential freedoms: Line 70  four essential freedoms:
70  </ul>  </ul>
71    
72  <p>  <p>
73  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
74  you should be free to redistribute copies, either with or without  freedoms.  Otherwise, it is nonfree.  While we can distinguish various
75  modifications, either gratis or charging a fee for distribution, to  nonfree distribution schemes in terms of how far they fall short of
76    being free, we consider them all equally unethical.</p>
77    
78    <p>In any given scenario, these freedoms must apply to whatever code
79    we plan to make use of, or lead others to make use of.  For instance,
80    consider a program A which automatically launches a program B to
81    handle some cases.  If we plan to distribute A as it stands, that
82    implies users will need B, so we need to judge whether both A and B
83    are free.  However, if we plan to modify A so that it doesn't use B,
84    only A needs to be free; we can ignore B.</p>
85    
86    <p>The rest of this page clarifies certain points about what makes
87    specific freedoms adequate or not.</p>
88    
89    <p>Freedom to distribute (freedoms 2 and 3) means you are free to
90    redistribute copies, either with or without modifications, either
91    gratis or charging a fee for distribution, to
92  <a href="#exportcontrol">anyone anywhere</a>.  Being free to do these  <a href="#exportcontrol">anyone anywhere</a>.  Being free to do these
93  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
94  for permission to do so.  for permission to do so.
# Line 95  for her purposes, but you are not entitl Line 113  for her purposes, but you are not entitl
113  </p>  </p>
114    
115  <p>  <p>
116    The freedom to run the program as you wish means that you are not
117    forbidden or stopped from doing so.  It has nothing to do with what
118    functionality the program has, or whether it is useful for what you
119    want to do.</p>
120    
121    <p>
122  The freedom to redistribute copies must include binary or executable  The freedom to redistribute copies must include binary or executable
123  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
124  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 144  the original.  If the program is deliver
144  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
145  practice known as &ldquo;tivoization&rdquo; or &ldquo;lockdown&rdquo;,  practice known as &ldquo;tivoization&rdquo; or &ldquo;lockdown&rdquo;,
146  or (in its practitioners' perverse terminology) as &ldquo;secure  or (in its practitioners' perverse terminology) as &ldquo;secure
147  boot&rdquo; &mdash; freedom 1 becomes a theoretical fiction rather  boot&rdquo; &mdash; freedom 1 becomes an empty pretense rather than a
148  than a practical freedom.  This is not sufficient.  In other words,  practical reality.  These binaries are not free
149  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.  
150  </p>  </p>
151    
152  <p>  <p>
# Line 154  cause, the software is not free. Line 177  cause, the software is not free.
177  <p>  <p>
178  However, certain kinds of rules about the manner of distributing free  However, certain kinds of rules about the manner of distributing free
179  software are acceptable, when they don't conflict with the central  software are acceptable, when they don't conflict with the central
180  freedoms.  For example, copyleft (very simply stated) is the rule that  freedoms.  For example, <a href="/copyleft/copyleft.html">copyleft</a>
181  when redistributing the program, you cannot add restrictions to deny  (very simply stated) is the rule that when redistributing the program,
182  other people the central freedoms.  This rule does not conflict with  you cannot add restrictions to deny other people the central freedoms.
183  the central freedoms; rather it protects them.  This rule does not conflict with the central freedoms; rather it
184    protects them.
185    </p>
186    
187    <p>
188    In the GNU project, we use copyleft to protect the four freedoms
189    legally for everyone.  We believe there are important reasons why
190    <a href="/philosophy/pragmatic.html">it is better to use
191    copyleft</a>.  However,
192    <a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware">
193    noncopylefted free software</a> is ethical
194    too.  See <a href="/philosophy/categories.html">Categories of Free
195    Software</a> for a description of how &ldquo;free software,&rdquo;
196    &ldquo;copylefted software&rdquo; and other categories of software
197    relate to each other.
198  </p>  </p>
199    
200  <p>  <p>
# Line 211  facility that allows you to specify the Line 248  facility that allows you to specify the
248  alias for the modified version.</p>  alias for the modified version.</p>
249    
250  <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>  
251  Sometimes government <a id="exportcontrol">export control regulations</a>  Sometimes government <a id="exportcontrol">export control regulations</a>
252  and trade sanctions can constrain your freedom to distribute copies of  and trade sanctions can constrain your freedom to distribute copies of
253  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 255  eliminate or override these restrictions
255  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
256  way, the restrictions will not affect activities and people outside the  way, the restrictions will not affect activities and people outside the
257  jurisdictions of these governments.  Thus, free software licenses  jurisdictions of these governments.  Thus, free software licenses
258  must not require obedience to any export regulations as a condition of  must not require obedience to any nontrivial export regulations as a
259  any of the essential freedoms.  condition of exercising any of the essential freedoms.
260    </p>
261    
262    <p>
263    Merely mentioning the existence of export regulations, without making
264    them a condition of the license itself, is acceptable since it does
265    not restrict users.  If an export regulation is actually trivial for
266    free software, then requiring it as a condition is not an actual
267    problem; however, it is a potential problem, since a later change in
268    export law could make the requirement nontrivial and thus render the
269    software nonfree.
270    </p>
271    
272    <p>
273    A free license may not require compliance with the license of a
274    nonfree program.  Thus, for instance, if a license requires you to
275    comply with the licenses of &ldquo;all the programs you use&rdquo;, in
276    the case of a user that runs nonfree programs this would require
277    compliance with the licenses of those nonfree programs; that makes the
278    license nonfree.
279    </p>
280    
281    <p>
282    It is acceptable for a free license to specify which jurisdiction's
283    law applies, or where litigation must be done, or both.
284  </p>  </p>
285    
286  <p>  <p>
# Line 324  free cultural works</a> applicable to an Line 374  free cultural works</a> applicable to an
374  <h3 id="open-source">Open Source?</h3>  <h3 id="open-source">Open Source?</h3>
375    
376  <p>  <p>
377  Another group has started using the term &ldquo;open source&rdquo; to mean  Another group uses the term &ldquo;open source&rdquo; to mean
378  something close (but not identical) to &ldquo;free software&rdquo;.  We  something close (but not identical) to &ldquo;free software&rdquo;.  We
379  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
380  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 390  was changed.</p>
390    
391  <ul>  <ul>
392    
393    <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
394    1.141</a>: Clarify which code needs to be free.</li>
395    
396    <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
397    1.135</a>: Say each time that freedom 0 is the freedom to run the program
398    as you wish.</li>
399    
400    <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
401    1.134</a>: Freedom 0 is not a matter of the program's functionality.</li>
402    
403    <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
404    1.131</a>: A free license may not require compliance with a nonfree license
405    of another program.</li>
406    
407    <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
408    1.129</a>: State explicitly that choice of law and choice of forum
409    specifications are allowed.  (This was always our policy.)</li>
410    
411    <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
412    1.122</a>: An export control requirement is a real problem if the
413    requirement is nontrivial; otherwise it is only a potential problem.</li>
414    
415    <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
416    1.118</a>: Clarification: the issue is limits on your right to modify,
417    not on what modifications you have made.  And modifications are not limited
418    to &ldquo;improvements&rdquo;</li>
419    
420  <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
421  1.111</a>: Clarify 1.77 by saying that only  1.111</a>: Clarify 1.77 by saying that only
422  retroactive <em>restrictions</em> are unacceptable.  The copyright  retroactive <em>restrictions</em> are unacceptable.  The copyright
# Line 424  versions you distribute to the author.</ Line 501  versions you distribute to the author.</
501  </ul>  </ul>
502    
503  <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
504  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
505  These changes are in other parts of the page.  You can review the  interpretations.  For instance, the list does not include changes in
506  complete list of changes to the page through  asides, formatting, spelling, punctuation, or other parts of the page.
507    You can review the complete list of changes to the page through
508  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
509  interface</a>.</p>  interface</a>.</p>
510    
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511    
512    </div><!-- for id="content", starts in the include above -->
513  <!--#include virtual="/server/footer.html" -->  <!--#include virtual="/server/footer.html" -->
   
514  <div id="footer">  <div id="footer">
515    <div class="unprintable">
516    
517  <p>  <p>Please send general FSF &amp; GNU inquiries to
 Please send FSF &amp; GNU inquiries to  
518  <a href="mailto:gnu@gnu.org">&lt;gnu@gnu.org&gt;</a>.  <a href="mailto:gnu@gnu.org">&lt;gnu@gnu.org&gt;</a>.
519  There are also <a href="/contact/">other ways to contact</a>  There are also <a href="/contact/">other ways to contact</a>
520  the FSF.  the FSF.  Broken links and other corrections or suggestions can be sent
521  <br />  to <a href="mailto:webmasters@gnu.org">&lt;webmasters@gnu.org&gt;</a>.</p>
522  Please send broken links and other corrections or suggestions to  
523  <a href="mailto:webmasters@gnu.org">&lt;webmasters@gnu.org&gt;</a>.  <p><!-- TRANSLATORS: Ignore the original text in this paragraph,
524  </p>          replace it with the translation of these two:
525    
526            We work hard and do our best to provide accurate, good quality
527            translations.  However, we are not exempt from imperfection.
528            Please send your comments and general suggestions in this regard
529            to <a href="mailto:web-translators@gnu.org">
530            &lt;web-translators@gnu.org&gt;</a>.</p>
531    
532            <p>For information on coordinating and submitting translations of
533            our web pages, see <a
534            href="/server/standards/README.translations.html">Translations
535            README</a>. -->
536    Please see the <a
537    href="/server/standards/README.translations.html">Translations
538    README</a> for information on coordinating and submitting translations
539    of this article.</p>
540    </div>
541    
542  <p>  <!-- Regarding copyright, in general, standalone pages (as opposed to
543  Please see the       files generated as part of manuals) on the GNU web server should
544  <a href="/server/standards/README.translations.html">Translations       be under CC BY-ND 4.0.  Please do NOT change or remove this
545  README</a> for information on coordinating and submitting       without talking with the webmasters or licensing team first.
546  translations of this article.       Please make sure the copyright date is consistent with the
547  </p>       document.  For web pages, it is ok to list just the latest year the
548         document was modified, or published.
549        
550         If you wish to list earlier years, that is ok too.
551         Either "2001, 2002, 2003" or "2001-2003" are ok for specifying
552         years, as long as each year in the range is in fact a copyrightable
553         year, i.e., a year in which the document was published (including
554         being publicly visible on the web or in a revision control system).
555        
556         There is more detail about copyright years in the GNU Maintainers
557         Information document, www.gnu.org/prep/maintain. -->
558    
559    <p>Copyright &copy; 1996, 2015&ndash;2002, 2004&ndash;2007, 2009&ndash;2015
560    Free Software Foundation, Inc.</p>
561    
 <p>  
 Copyright &copy; 1996-2002, 2004-2007, 2009, 2010, 2012 Free Software  
 Foundation, Inc.  
 </p>  
562  <p>This page is licensed under a <a rel="license"  <p>This page is licensed under a <a rel="license"
563  href="http://creativecommons.org/licenses/by-nd/3.0/us/">Creative  href="http://creativecommons.org/licenses/by-nd/4.0/">Creative
564  Commons Attribution-NoDerivs 3.0 United States License</a>.  Commons Attribution-NoDerivatives 4.0 International License</a>.</p>
 </p>  
565    
566  <!--#include virtual="/server/bottom-notes.html" -->  <!--#include virtual="/server/bottom-notes.html" -->
567    
568  <p>Updated:  <p class="unprintable">Updated:
569  <!-- timestamp start -->  <!-- timestamp start -->
570  $Date$  $Date$
571  <!-- timestamp end -->  <!-- timestamp end -->
572  </p>  </p>
573  </div>  </div>
   
   
574  </div>  </div>
   
575  </body>  </body>
576  </html>  </html>

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