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<title>What is Free Software? |
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- GNU Project - Free Software Foundation</title> |
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<div class="article reduced-width"> |
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<h2>What is Free Software?</h2> |
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<div class="thin"></div> |
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|
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<div class="important"> |
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<p> |
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“Free software” means software that respects users' |
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freedom and community. Roughly, it means that <b>the users have the |
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freedom to run, copy, distribute, study, change and improve the |
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software</b>. Thus, “free software” is a matter of |
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liberty, not price. To understand the concept, you should think of |
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“free” as in “free speech,” not as in |
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“free beer.” We sometimes call it “libre |
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software,” borrowing the French or Spanish word for |
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“free” as in freedom, to show we do not mean the software |
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is gratis. |
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</p> |
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|
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<p> |
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You may have paid money to get copies of a free program, or you may |
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have obtained copies at no charge. But regardless of how you got your |
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copies, you always have the freedom to copy and change the software, |
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even to <a href="/philosophy/selling.html">sell copies</a>. |
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</p> |
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</div> |
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|
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<p> |
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We campaign for these freedoms because everyone deserves them. With |
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these freedoms, the users (both individually and collectively) control |
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the program and what it does for them. When users don't control the |
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program, we call it a “nonfree” or |
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“proprietary” program. The nonfree program controls the |
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users, and the developer controls the program; this makes the |
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program <a href="/philosophy/free-software-even-more-important.html"> |
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an instrument of unjust power</a>. |
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</p> |
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|
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<p> |
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“Open source” is something different: it has a very |
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different philosophy based on different values. Its practical |
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definition is different too, but nearly all open source programs are |
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in fact free. We explain the |
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difference in <a href="/philosophy/open-source-misses-the-point.html"> |
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Why “Open Source” misses the point of Free Software</a>. |
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</p> |
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|
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<div class="toc"> |
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<hr class="no-display" /> |
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<h3 class="no-display">Table of contents</h3> |
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<ul> |
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<li><a href="#fs-definition">The Free Software Definition</a> |
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<ul> |
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<li><a href="#four-freedoms">The four essential freedoms</a></li> |
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<li><a href="#selling">Free software <em>can</em> be commercial</a></li> |
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</ul> |
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</li> |
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<li><a href="#clarifying">Clarifying the Boundary Between Free and Nonfree</a> |
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<ul> |
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<li><a href="#run-the-program">The freedom to run the program as you |
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wish</a></li> |
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<li><a href="#make-changes">The freedom to study the source code and make |
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changes</a></li> |
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<li><a href="#redistribute">The freedom to redistribute if you wish: |
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basic requirements</a></li> |
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<li><a href="#copyleft">Copyleft</a></li> |
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<li><a href="#packaging">Rules about packaging and distribution |
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details</a></li> |
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<li><a href="#exportcontrol">Export regulations</a></li> |
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<li><a href="#legal-details">Legal considerations</a></li> |
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<li><a href="#contracts">Contract-based licenses</a></li> |
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</ul> |
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</li> |
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<li><a href="#in-practice">The Free Software Definition in Practice</a> |
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<ul> |
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<li><a href="#interpretation">How we interpret these criteria</a></li> |
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<li><a href="#get-help">Get help with free licenses</a></li> |
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<li><a href="#terminology">Use the right words when talking about free |
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software</a></li> |
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</ul> |
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</li> |
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<li><a href="#beyond-software">Beyond Software</a></li> |
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<li><a href="#History">History</a></li> |
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</ul> |
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</div> |
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|
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<div class="edu-note" id="fsf-licensing" role="complementary"> |
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<p style="font-size:80%"> |
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Have a question about free software licensing not answered here? |
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See our other <a href="http://www.fsf.org/licensing">licensing resources</a>, |
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and if necessary contact the FSF Compliance Lab |
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at <a href="mailto:licensing@fsf.org">licensing@fsf.org</a>.</p> |
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<hr class="no-display" /> |
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</div> |
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|
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|
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<h3 id="fs-definition">The Free Software Definition</h3> |
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|
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<p> |
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The free software definition presents the criteria for whether a |
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particular software program qualifies as free software. From time to |
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time we revise this definition, to clarify it or to resolve questions |
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about subtle issues. See the <a href="#History">History section</a> |
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below for a list of changes that affect the definition of free |
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software. |
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</p> |
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|
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<h4 id="four-freedoms">The four essential freedoms</h4> |
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<p> |
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A program is free software if the program's users have the |
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four essential freedoms: <a href="#f1">[1]</a> |
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</p> |
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|
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<ul class="important"> |
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<li>The freedom to run the program as you wish, |
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for any purpose (freedom 0).</li> |
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<li>The freedom to study how the program works, and change it so it |
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does your computing as you wish (freedom 1). Access to the source |
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code is a precondition for this. |
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</li> |
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<li>The freedom to redistribute copies so you can help others |
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(freedom 2). |
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</li> |
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<li>The freedom to distribute copies of your modified versions |
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to others (freedom 3). By doing this you can give the whole |
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community a chance to benefit from your changes. |
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Access to the source code is a precondition for this. |
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</li> |
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</ul> |
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|
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<p> |
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A program is free software if it gives users adequately all of these |
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freedoms. Otherwise, it is nonfree. While we can distinguish various |
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nonfree distribution schemes in terms of how far they fall short of |
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being free, we consider them all equally unethical.</p> |
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|
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<p>In any given scenario, these freedoms must apply to whatever code |
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we plan to make use of, or lead others to make use of. For instance, |
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consider a program A which automatically launches a program B to |
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handle some cases. If we plan to distribute A as it stands, that |
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implies users will need B, so we need to judge whether both A and B |
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are free. However, if we plan to modify A so that it doesn't use B, |
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only A needs to be free; B is not pertinent to that plan.</p> |
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|
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|
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<h4 id="selling">Free software <em>can</em> be commercial</h4> |
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|
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<p> |
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“Free software” does not mean “noncommercial.” |
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On the contrary, a free program must be available for commercial use, |
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commercial development, and commercial distribution. This policy is |
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of fundamental importance—without this, free software could not |
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achieve its aims. |
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</p> |
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|
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<p> |
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We want to invite everyone to use the GNU system, including businesses |
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and their workers. That requires allowing commercial use. We hope |
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that free replacement programs will supplant comparable proprietary |
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programs, but they can't do that if businesses are forbidden to use |
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them. We want commercial products that contain software to include |
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the GNU system, and that would constitute commercial distribution for |
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a price. Commercial development of free software is no longer |
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unusual; such free commercial software is very important. Paid, |
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professional support for free software fills an important need. |
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</p> |
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|
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<p> |
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Thus, to exclude commercial use, commercial development or commercial |
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distribution would hobble the free software community and obstruct its |
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path to success. We must conclude that a program licensed with such |
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restrictions does not qualify as free software. |
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</p> |
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|
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<p> |
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A free program must offer the four freedoms to any would-be user that |
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obtains a copy of the software, who has complied thus far with the |
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conditions of the free license covering the software in any previous |
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distribution of it. Putting some of the freedoms off limits to some |
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users, or requiring that users pay, in money or in kind, to exercise |
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them, is tantamount to not granting the freedoms in question, and thus |
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renders the program nonfree. |
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</p> |
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|
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|
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<h3 id="clarifying">Clarifying the Boundary Between Free and Nonfree</h3> |
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|
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<p>In the rest of this article we explain more precisely how far the |
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various freedoms need to extend, on various issues, in order for a |
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program to be free.</p> |
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|
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<h4 id="run-the-program">The freedom to run the program as you wish</h4> |
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|
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<p> |
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The freedom to run the program means the freedom for any kind of person |
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or organization to use it on any kind of computer system, for any kind of |
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overall job and purpose, without being required to communicate about it |
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with the developer or any other specific entity. In this freedom, it is |
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the <em>user's</em> purpose that matters, not the <em>developer's</em> |
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purpose; you as a user are free to run the program for your purposes, |
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and if you distribute it to someone else, she is then free to run it |
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for her purposes, but you are not entitled to impose your purposes on her. |
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</p> |
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|
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<p> |
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The freedom to run the program as you wish means that you are not |
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forbidden or stopped from making it run. This has nothing to do with what |
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functionality the program has, whether it is technically capable of |
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functioning in any given environment, or whether it is useful for any |
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particular computing activity.</p> |
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|
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<p>For example, if the code arbitrarily rejects certain meaningful |
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inputs—or even fails unconditionally—that may make the |
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program less useful, perhaps even totally useless, but it does not |
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deny users the freedom to run the program, so it does not conflict |
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with freedom 0. If the program is free, the users can overcome the |
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loss of usefulness, because freedoms 1 and 3 permit users and |
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communities to make and distribute modified versions without the |
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arbitrary nuisance code.</p> |
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|
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<p>“As you wish” includes, optionally, “not at |
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all” if that is what you wish. So there is no need for a |
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separate “freedom not to run a program.”</p> |
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|
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<h4 id="make-changes">The freedom to study the source code and make changes</h4> |
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|
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<p> |
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In order for freedoms 1 and 3 (the freedom to make changes and the |
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freedom to publish the changed versions) to be meaningful, you need to have |
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access to the source code of the program. Therefore, accessibility of |
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source code is a necessary condition for free software. Obfuscated |
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“source code” is not real source code and does not count |
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as source code. |
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</p> |
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|
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<p> |
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Freedom 1 includes the freedom to use your changed version in place of |
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the original. If the program is delivered in a product designed to |
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run someone else's modified versions but refuse to run yours—a |
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practice known as “tivoization” or “lockdown,” |
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or (in its practitioners' perverse terminology) as “secure |
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boot”—freedom 1 becomes an empty pretense rather than a |
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practical reality. These binaries are not free |
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software even if the source code they are compiled from is free. |
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</p> |
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|
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<p> |
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One important way to modify a program is by merging in available free |
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subroutines and modules. If the program's license says that you |
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cannot merge in a suitably licensed existing module—for instance, if it |
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requires you to be the copyright holder of any code you add—then the |
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license is too restrictive to qualify as free. |
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</p> |
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|
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<p> |
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Whether a change constitutes an improvement is a subjective matter. |
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If your right to modify a program is limited, in substance, to changes that |
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someone else considers an improvement, that program is not free. |
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</p> |
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|
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<p> |
280 |
One special case of freedom 1 is to delete the program's code so it |
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returns after doing nothing, or make it invoke some other program. |
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Thus, freedom 1 includes the “freedom to delete the program.” |
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</p> |
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|
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<h4 id="redistribute">The freedom to redistribute if you wish: basic |
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requirements</h4> |
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|
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<p>Freedom to distribute (freedoms 2 and 3) means you are free to |
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redistribute copies, either with or without modifications, either |
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gratis or charging a fee for distribution, to |
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<a href="#exportcontrol">anyone anywhere</a>. Being free to do these |
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things means (among other things) that you do not have to ask or pay |
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for permission to do so. |
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</p> |
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|
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<p> |
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You should also have the freedom to make modifications and use them |
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privately in your own work or play, without even mentioning that they |
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exist. If you do publish your changes, you should not be required to |
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notify anyone in particular, or in any particular way. |
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</p> |
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|
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<p> |
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Freedom 3 includes the freedom to release your modified versions |
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as free software. A free license may also permit other ways of |
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releasing them; in other words, it does not have to be |
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a <a href="/licenses/copyleft.html">copyleft</a> license. However, a |
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license that requires modified versions to be nonfree does not qualify |
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as a free license. |
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</p> |
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|
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<p> |
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The freedom to redistribute copies must include binary or executable |
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forms of the program, as well as source code, for both modified and |
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unmodified versions. (Distributing programs in runnable form is necessary |
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for conveniently installable free operating systems.) It is OK if there |
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is no way to produce a binary or executable form for a certain program |
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(since some languages don't support that feature), but you must have the |
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freedom to redistribute such forms should you find or develop a way to |
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make them. |
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</p> |
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|
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<h4 id="copyleft">Copyleft</h4> |
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|
325 |
<p> |
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Certain kinds of rules about the manner of distributing free |
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software are acceptable, when they don't conflict with the central |
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freedoms. For example, <a href="/licenses/copyleft.html">copyleft</a> |
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(very simply stated) is the rule that when redistributing the program, |
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you cannot add restrictions to deny other people the central freedoms. |
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This rule does not conflict with the central freedoms; rather it |
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protects them. |
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</p> |
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|
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<p> |
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In the GNU project, we use copyleft to protect the four freedoms |
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legally for everyone. We believe there are important reasons why |
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<a href="/philosophy/pragmatic.html">it is better to use |
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copyleft</a>. However, |
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<a href="/philosophy/categories.html#Non-CopyleftedFreeSoftware"> |
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noncopylefted free software</a> is ethical |
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too. See <a href="/philosophy/categories.html">Categories of Free |
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Software</a> for a description of how “free software,” |
344 |
“copylefted software” and other categories of software |
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relate to each other. |
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</p> |
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|
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<h4 id="packaging">Rules about packaging and distribution details</h4> |
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|
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<p> |
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Rules about how to package a modified version are acceptable, |
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if they don't substantively limit your freedom to release modified |
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versions, or your freedom to make and use modified versions privately. |
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Thus, it is acceptable for the license to require that you change the |
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name of the modified version, remove a logo, or identify your |
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modifications as yours. As long as these requirements are not so |
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burdensome that they effectively hamper you from releasing your |
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changes, they are acceptable; you're already making other changes to |
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the program, so you won't have trouble making a few more. |
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</p> |
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|
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<p> |
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Rules that “if you make your version available in this way, you |
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must make it available in that way also” can be acceptable too, |
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on the same condition. An example of such an acceptable rule is one |
366 |
saying that if you have distributed a |
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modified version and a previous developer asks for a copy of it, you |
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must send one. (Note that such a rule still leaves you the choice of |
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whether to distribute your version at all.) Rules that require release |
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of source code to the users for versions that you put into public use |
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are also acceptable. |
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</p> |
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|
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<p> |
375 |
A special issue arises when a license requires changing the name by |
376 |
which the program will be invoked from other programs. That |
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effectively hampers you from releasing your changed version so that it |
378 |
can replace the original when invoked by those other programs. This |
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sort of requirement is acceptable only if there's a suitable aliasing |
380 |
facility that allows you to specify the original program's name as an |
381 |
alias for the modified version.</p> |
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|
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<h4 id="exportcontrol">Export regulations</h4> |
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|
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<p> |
386 |
Sometimes government export control regulations |
387 |
and trade sanctions can constrain your freedom to distribute copies of |
388 |
programs internationally. Software developers do not have the power to |
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eliminate or override these restrictions, but what they can and must do |
390 |
is refuse to impose them as conditions of use of the program. In this |
391 |
way, the restrictions will not affect activities and people outside the |
392 |
jurisdictions of these governments. Thus, free software licenses |
393 |
must not require obedience to any nontrivial export regulations as a |
394 |
condition of exercising any of the essential freedoms. |
395 |
</p> |
396 |
|
397 |
<p> |
398 |
Merely mentioning the existence of export regulations, without making |
399 |
them a condition of the license itself, is acceptable since it does |
400 |
not restrict users. If an export regulation is actually trivial for |
401 |
free software, then requiring it as a condition is not an actual |
402 |
problem; however, it is a potential problem, since a later change in |
403 |
export law could make the requirement nontrivial and thus render the |
404 |
software nonfree. |
405 |
</p> |
406 |
|
407 |
<h4 id="legal-details">Legal considerations</h4> |
408 |
|
409 |
<p> |
410 |
In order for these freedoms to be real, they must be permanent and |
411 |
irrevocable as long as you do nothing wrong; if the developer of the |
412 |
software has the power to revoke the license, or retroactively add |
413 |
restrictions to its terms, without your doing anything wrong to give |
414 |
cause, the software is not free. |
415 |
</p> |
416 |
|
417 |
<p> |
418 |
A free license may not require compliance with the license of a |
419 |
nonfree program. Thus, for instance, if a license requires you to |
420 |
comply with the licenses of “all the programs you use,” in |
421 |
the case of a user that runs nonfree programs this would require |
422 |
compliance with the licenses of those nonfree programs; that makes the |
423 |
license nonfree. |
424 |
</p> |
425 |
|
426 |
<p> |
427 |
It is acceptable for a free license to specify which jurisdiction's |
428 |
law applies, or where litigation must be done, or both. |
429 |
</p> |
430 |
|
431 |
<h4 id="contracts">Contract-based licenses</h4> |
432 |
|
433 |
<p> |
434 |
Most free software licenses are based on copyright, and there are limits |
435 |
on what kinds of requirements can be imposed through copyright. If a |
436 |
copyright-based license respects freedom in the ways described above, it |
437 |
is unlikely to have some other sort of problem that we never anticipated |
438 |
(though this does happen occasionally). However, some free software |
439 |
licenses are based on contracts, and contracts can impose a much larger |
440 |
range of possible restrictions. That means there are many possible ways |
441 |
such a license could be unacceptably restrictive and nonfree. |
442 |
</p> |
443 |
|
444 |
<p> |
445 |
We can't possibly list all the ways that might happen. If a |
446 |
contract-based license restricts the user in an unusual way that |
447 |
copyright-based licenses cannot, and which isn't mentioned here as |
448 |
legitimate, we will have to think about it, and we will probably conclude |
449 |
it is nonfree. |
450 |
</p> |
451 |
|
452 |
<h3 id="in-practice">The Free Software Definition in Practice</h3> |
453 |
|
454 |
<h4 id="interpretation">How we interpret these criteria</h4> |
455 |
|
456 |
<p> |
457 |
Note that criteria such as those stated in this free software |
458 |
definition require careful thought for their interpretation. To decide |
459 |
whether a specific software license qualifies as a free software license, |
460 |
we judge it based on these criteria to determine whether it fits their |
461 |
spirit as well as the precise words. If a license includes unconscionable |
462 |
restrictions, we reject it, even if we did not anticipate the issue |
463 |
in these criteria. Sometimes a license requirement raises an issue |
464 |
that calls for extensive thought, including discussions with a lawyer, |
465 |
before we can decide if the requirement is acceptable. When we reach |
466 |
a conclusion about a new issue, we often update these criteria to make |
467 |
it easier to see why certain licenses do or don't qualify. |
468 |
</p> |
469 |
|
470 |
<h4 id="get-help">Get help with free licenses</h4> |
471 |
|
472 |
<p> |
473 |
If you are interested in whether a specific license qualifies as a free |
474 |
software license, see our <a href="/licenses/license-list.html">list |
475 |
of licenses</a>. If the license you are concerned with is not |
476 |
listed there, you can ask us about it by sending us email at |
477 |
<a href="mailto:licensing@gnu.org"><licensing@gnu.org></a>. |
478 |
</p> |
479 |
|
480 |
<p> |
481 |
If you are contemplating writing a new license, please contact the |
482 |
Free Software Foundation first by writing to that address. The |
483 |
proliferation of different free software licenses means increased work |
484 |
for users in understanding the licenses; we may be able to help you |
485 |
find an existing free software license that meets your needs. |
486 |
</p> |
487 |
|
488 |
<p> |
489 |
If that isn't possible, if you really need a new license, with our |
490 |
help you can ensure that the license really is a free software license |
491 |
and avoid various practical problems. |
492 |
</p> |
493 |
|
494 |
<h4 id="terminology">Use the right words when talking about free software</h4> |
495 |
|
496 |
<p> |
497 |
When talking about free software, it is best to avoid using terms |
498 |
like “give away” or “for free,” because those terms imply that |
499 |
the issue is about price, not freedom. Some common terms such |
500 |
as “piracy” embody opinions we hope you won't endorse. See |
501 |
<a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases that |
502 |
are Worth Avoiding</a> for a discussion of these terms. We also have |
503 |
a list of proper <a href="/philosophy/fs-translations.html">translations of |
504 |
“free software”</a> into various languages. |
505 |
</p> |
506 |
|
507 |
<p id="open-source"> |
508 |
Another group uses the term “open source” to mean |
509 |
something close (but not identical) to “free software.” We |
510 |
prefer the term “free software” because, once you have heard that |
511 |
it refers to freedom rather than price, it calls to mind freedom. The |
512 |
word “open” never refers to freedom. |
513 |
</p> |
514 |
|
515 |
<h3 id="beyond-software">Beyond Software</h3> |
516 |
|
517 |
<p> |
518 |
<a href="/philosophy/free-doc.html">Software manuals must be free</a>, |
519 |
for the same reasons that software must be free, and because the |
520 |
manuals are in effect part of the software. |
521 |
</p> |
522 |
|
523 |
<p> |
524 |
The same arguments also make sense for other kinds of works of |
525 |
practical use—that is to say, works that embody useful knowledge, |
526 |
such as educational works and reference |
527 |
works. <a href="https://wikipedia.org">Wikipedia</a> is the best-known |
528 |
example. |
529 |
</p> |
530 |
|
531 |
<p> |
532 |
Any kind of work <em>can</em> be free, and the definition of free software |
533 |
has been extended to a definition of <a href="http://freedomdefined.org/"> |
534 |
free cultural works</a> applicable to any kind of works. |
535 |
</p> |
536 |
|
537 |
<h3 id="History">History</h3> |
538 |
|
539 |
<p>From time to time we revise this Free Software Definition. Here is |
540 |
the list of substantive changes, along with links to show exactly what |
541 |
was changed.</p> |
542 |
|
543 |
<ul> |
544 |
|
545 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.168&r2=1.169">Version |
546 |
1.169</a>: Explain more clearly why the four freedoms must apply |
547 |
to commercial activity. Explain why the four freedoms imply the |
548 |
freedom not to run the program and the freedom to delete it, so there |
549 |
is no need to state those as separate requirements.</li> |
550 |
|
551 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.164&r2=1.165">Version |
552 |
1.165</a>: Clarify that arbitrary annoyances in the code do not |
553 |
negate freedom 0, and that freedoms 1 and 3 enable users to remove them.</li> |
554 |
|
555 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.152&r2=1.153">Version |
556 |
1.153</a>: Clarify that freedom to run the program means nothing stops |
557 |
you from making it run.</li> |
558 |
|
559 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.140&r2=1.141">Version |
560 |
1.141</a>: Clarify which code needs to be free.</li> |
561 |
|
562 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.134&r2=1.135">Version |
563 |
1.135</a>: Say each time that freedom 0 is the freedom to run the program |
564 |
as you wish.</li> |
565 |
|
566 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.133&r2=1.134">Version |
567 |
1.134</a>: Freedom 0 is not a matter of the program's functionality.</li> |
568 |
|
569 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.130&r2=1.131">Version |
570 |
1.131</a>: A free license may not require compliance with a nonfree license |
571 |
of another program.</li> |
572 |
|
573 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.128&r2=1.129">Version |
574 |
1.129</a>: State explicitly that choice of law and choice of forum |
575 |
specifications are allowed. (This was always our policy.)</li> |
576 |
|
577 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.121&r2=1.122">Version |
578 |
1.122</a>: An export control requirement is a real problem if the |
579 |
requirement is nontrivial; otherwise it is only a potential problem.</li> |
580 |
|
581 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.117&r2=1.118">Version |
582 |
1.118</a>: Clarification: the issue is limits on your right to modify, |
583 |
not on what modifications you have made. And modifications are not limited |
584 |
to “improvements”</li> |
585 |
|
586 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.110&r2=1.111">Version |
587 |
1.111</a>: Clarify 1.77 by saying that only |
588 |
retroactive <em>restrictions</em> are unacceptable. The copyright |
589 |
holders can always grant additional <em>permission</em> for use of the |
590 |
work by releasing the work in another way in parallel.</li> |
591 |
|
592 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.104&r2=1.105">Version |
593 |
1.105</a>: Reflect, in the brief statement of freedom 1, the point |
594 |
(already stated in version 1.80) that it includes really using your modified |
595 |
version for your computing.</li> |
596 |
|
597 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.91&r2=1.92">Version |
598 |
1.92</a>: Clarify that obfuscated code does not qualify as source code.</li> |
599 |
|
600 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.89&r2=1.90">Version |
601 |
1.90</a>: Clarify that freedom 3 means the right to distribute copies |
602 |
of your own modified or improved version, not a right to participate |
603 |
in someone else's development project.</li> |
604 |
|
605 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.88&r2=1.89">Version |
606 |
1.89</a>: Freedom 3 includes the right to release modified versions as |
607 |
free software.</li> |
608 |
|
609 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.79&r2=1.80">Version |
610 |
1.80</a>: Freedom 1 must be practical, not just theoretical; |
611 |
i.e., no tivoization.</li> |
612 |
|
613 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.76&r2=1.77">Version |
614 |
1.77</a>: Clarify that all retroactive changes to the license are |
615 |
unacceptable, even if it's not described as a complete |
616 |
replacement.</li> |
617 |
|
618 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.73&r2=1.74">Version |
619 |
1.74</a>: Four clarifications of points not explicit enough, or stated |
620 |
in some places but not reflected everywhere: |
621 |
<ul> |
622 |
<li>"Improvements" does not mean the license can |
623 |
substantively limit what kinds of modified versions you can release. |
624 |
Freedom 3 includes distributing modified versions, not just changes.</li> |
625 |
<li>The right to merge in existing modules |
626 |
refers to those that are suitably licensed.</li> |
627 |
<li>Explicitly state the conclusion of the point about export controls.</li> |
628 |
<li>Imposing a license change constitutes revoking the old license.</li> |
629 |
</ul> |
630 |
</li> |
631 |
|
632 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.56&r2=1.57">Version |
633 |
1.57</a>: Add "Beyond Software" section.</li> |
634 |
|
635 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.45&r2=1.46">Version |
636 |
1.46</a>: Clarify whose purpose is significant in the freedom to run |
637 |
the program for any purpose.</li> |
638 |
|
639 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.40&r2=1.41">Version |
640 |
1.41</a>: Clarify wording about contract-based licenses.</li> |
641 |
|
642 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.39&r2=1.40">Version |
643 |
1.40</a>: Explain that a free license must allow to you use other |
644 |
available free software to create your modifications.</li> |
645 |
|
646 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.38&r2=1.39">Version |
647 |
1.39</a>: Note that it is acceptable for a license to require you to |
648 |
provide source for versions of the software you put into public |
649 |
use.</li> |
650 |
|
651 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.30&r2=1.31">Version |
652 |
1.31</a>: Note that it is acceptable for a license to require you to |
653 |
identify yourself as the author of modifications. Other minor |
654 |
clarifications throughout the text.</li> |
655 |
|
656 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.22&r2=1.23">Version |
657 |
1.23</a>: Address potential problems related to contract-based |
658 |
licenses.</li> |
659 |
|
660 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.15&r2=1.16">Version |
661 |
1.16</a>: Explain why distribution of binaries is important.</li> |
662 |
|
663 |
<li><a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.10&r2=1.11">Version |
664 |
1.11</a>: Note that a free license may require you to send a copy of |
665 |
versions you distribute to previous developers on request.</li> |
666 |
|
667 |
</ul> |
668 |
|
669 |
<p>There are gaps in the version numbers shown above because there are |
670 |
other changes in this page that do not affect the definition or its |
671 |
interpretations. For instance, the list does not include changes in |
672 |
asides, formatting, spelling, punctuation, or other parts of the page. |
673 |
You can review the complete list of changes to the page through |
674 |
the <a href="//web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&view=log">cvsweb |
675 |
interface</a>.</p> |
676 |
<div class="column-limit"></div> |
677 |
|
678 |
<h3 class="footnote">Footnote</h3> |
679 |
<ol> |
680 |
<li id="f1">The reason they are numbered 0, 1, 2 and 3 is historical. Around |
681 |
1990 there were three freedoms, numbered 1, 2 and 3. Then we realized that |
682 |
the freedom to run the program needed to be mentioned explicitly. |
683 |
It was clearly more basic than the other three, so it properly should |
684 |
precede them. Rather than renumber the others, we made it freedom 0.</li> |
685 |
</ol> |
686 |
</div> |
687 |
|
688 |
</div><!-- for id="content", starts in the include above --> |
689 |
<!--#include virtual="/server/footer.html" --> |
690 |
<div id="footer" role="contentinfo"> |
691 |
<div class="unprintable"> |
692 |
|
693 |
<p>Please send general FSF & GNU inquiries to |
694 |
<a href="mailto:gnu@gnu.org"><gnu@gnu.org></a>. |
695 |
There are also <a href="/contact/">other ways to contact</a> |
696 |
the FSF. Broken links and other corrections or suggestions can be sent |
697 |
to <a href="mailto:webmasters@gnu.org"><webmasters@gnu.org></a>.</p> |
698 |
|
699 |
<p><!-- TRANSLATORS: Ignore the original text in this paragraph, |
700 |
replace it with the translation of these two: |
701 |
|
702 |
We work hard and do our best to provide accurate, good quality |
703 |
translations. However, we are not exempt from imperfection. |
704 |
Please send your comments and general suggestions in this regard |
705 |
to <a href="mailto:web-translators@gnu.org"> |
706 |
<web-translators@gnu.org></a>.</p> |
707 |
|
708 |
<p>For information on coordinating and contributing translations of |
709 |
our web pages, see <a |
710 |
href="/server/standards/README.translations.html">Translations |
711 |
README</a>. --> |
712 |
Please see the <a |
713 |
href="/server/standards/README.translations.html">Translations |
714 |
README</a> for information on coordinating and contributing translations |
715 |
of this article.</p> |
716 |
</div> |
717 |
|
718 |
<!-- Regarding copyright, in general, standalone pages (as opposed to |
719 |
files generated as part of manuals) on the GNU web server should |
720 |
be under CC BY-ND 4.0. Please do NOT change or remove this |
721 |
without talking with the webmasters or licensing team first. |
722 |
Please make sure the copyright date is consistent with the |
723 |
document. For web pages, it is ok to list just the latest year the |
724 |
document was modified, or published. |
725 |
|
726 |
If you wish to list earlier years, that is ok too. |
727 |
Either "2001, 2002, 2003" or "2001-2003" are ok for specifying |
728 |
years, as long as each year in the range is in fact a copyrightable |
729 |
year, i.e., a year in which the document was published (including |
730 |
being publicly visible on the web or in a revision control system). |
731 |
|
732 |
There is more detail about copyright years in the GNU Maintainers |
733 |
Information document, www.gnu.org/prep/maintain. --> |
734 |
|
735 |
<p>Copyright © 1996-2002, 2004-2019, 2021 |
736 |
Free Software Foundation, Inc.</p> |
737 |
|
738 |
<p>This page is licensed under a <a rel="license" |
739 |
href="http://creativecommons.org/licenses/by-nd/4.0/">Creative |
740 |
Commons Attribution-NoDerivatives 4.0 International License</a>.</p> |
741 |
|
742 |
<!--#include virtual="/server/bottom-notes.html" --> |
743 |
|
744 |
<p class="unprintable">Updated: |
745 |
<!-- timestamp start --> |
746 |
$Date: 2021/08/31 11:39:00 $ |
747 |
<!-- timestamp end --> |
748 |
</p> |
749 |
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