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<h2>What is free software?</h2> |
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|
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<div class="article"> |
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<h3>The Free Software Definition</h3> |
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|
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<blockquote class="note" id="fsf-licensing"><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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</blockquote> |
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|
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<div class="comment"> |
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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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<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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</div> |
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|
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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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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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<h4> The four essential freedoms</h4> |
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|
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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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<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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<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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|
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<h3>Clarifying the line at various points</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>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, optonally, “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>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> |
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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>The freedom to redistribute if you wish: basic 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="/copyleft/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>Copyleft</h4> |
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|
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<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="/copyleft/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,” |
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“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>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 |
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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> |
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A special issue arises when a license requires changing the name by |
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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 |
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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 |
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facility that allows you to specify the original program's name as an |
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alias for the modified version.</p> |
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|
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<h4>Export regulations</h4> |
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|
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<p> |
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Sometimes government <a id="exportcontrol">export control regulations</a> |
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and trade sanctions can constrain your freedom to distribute copies of |
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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 |
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is refuse to impose them as conditions of use of the program. In this |
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way, the restrictions will not affect activities and people outside the |
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jurisdictions of these governments. Thus, free software licenses |
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must not require obedience to any nontrivial export regulations as a |
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condition of exercising any of the essential freedoms. |
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</p> |
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|
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<p> |
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Merely mentioning the existence of export regulations, without making |
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them a condition of the license itself, is acceptable since it does |
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not restrict users. If an export regulation is actually trivial for |
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free software, then requiring it as a condition is not an actual |
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problem; however, it is a potential problem, since a later change in |
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export law could make the requirement nontrivial and thus render the |
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software nonfree. |
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</p> |
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|
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<h4>Legal considerations</h4> |
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|
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<p> |
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In order for these freedoms to be real, they must be permanent and |
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irrevocable as long as you do nothing wrong; if the developer of the |
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software has the power to revoke the license, or retroactively add |
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restrictions to its terms, without your doing anything wrong to give |
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cause, the software is not free. |
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</p> |
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|
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<p> |
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A free license may not require compliance with the license of a |
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nonfree program. Thus, for instance, if a license requires you to |
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comply with the licenses of “all the programs you use”, in |
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the case of a user that runs nonfree programs this would require |
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compliance with the licenses of those nonfree programs; that makes the |
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license nonfree. |
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</p> |
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|
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<p> |
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It is acceptable for a free license to specify which jurisdiction's |
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law applies, or where litigation must be done, or both. |
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</p> |
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|
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<h4>Contract-based licenses</h4> |
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|
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<p> |
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Most free software licenses are based on copyright, and there are limits |
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on what kinds of requirements can be imposed through copyright. If a |
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copyright-based license respects freedom in the ways described above, it |
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is unlikely to have some other sort of problem that we never anticipated |
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(though this does happen occasionally). However, some free software |
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licenses are based on contracts, and contracts can impose a much larger |
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range of possible restrictions. That means there are many possible ways |
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such a license could be unacceptably restrictive and nonfree. |
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</p> |
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|
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<p> |
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We can't possibly list all the ways that might happen. If a |
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contract-based license restricts the user in an unusual way that |
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copyright-based licenses cannot, and which isn't mentioned here as |
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legitimate, we will have to think about it, and we will probably conclude |
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it is nonfree. |
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</p> |
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|
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<h4>Use the right words when talking about free software</h4> |
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|
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<p> |
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When talking about free software, it is best to avoid using terms |
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like “give away” or “for free,” because those terms imply that |
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the issue is about price, not freedom. Some common terms such |
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as “piracy” embody opinions we hope you won't endorse. See |
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<a href="/philosophy/words-to-avoid.html">Confusing Words and Phrases that |
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are Worth Avoiding</a> for a discussion of these terms. We also have |
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a list of proper <a href="/philosophy/fs-translations.html">translations of |
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“free software”</a> into various languages. |
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</p> |
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|
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<h4>How we interpret these criteria</h4> |
416 |
|
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<p> |
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Finally, note that criteria such as those stated in this free software |
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definition require careful thought for their interpretation. To decide |
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whether a specific software license qualifies as a free software license, |
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we judge it based on these criteria to determine whether it fits their |
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spirit as well as the precise words. If a license includes unconscionable |
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restrictions, we reject it, even if we did not anticipate the issue |
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in these criteria. Sometimes a license requirement raises an issue |
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that calls for extensive thought, including discussions with a lawyer, |
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before we can decide if the requirement is acceptable. When we reach |
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a conclusion about a new issue, we often update these criteria to make |
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it easier to see why certain licenses do or don't qualify. |
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</p> |
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|
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<h4>Get help with free licenses</h4> |
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|
433 |
<p> |
434 |
If you are interested in whether a specific license qualifies as a free |
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software license, see our <a href="/licenses/license-list.html">list |
436 |
of licenses</a>. If the license you are concerned with is not |
437 |
listed there, you can ask us about it by sending us email at |
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<a href="mailto:licensing@gnu.org"><licensing@gnu.org></a>. |
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</p> |
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|
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<p> |
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If you are contemplating writing a new license, please contact the |
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Free Software Foundation first by writing to that address. The |
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proliferation of different free software licenses means increased work |
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for users in understanding the licenses; we may be able to help you |
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find an existing free software license that meets your needs. |
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</p> |
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|
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<p> |
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If that isn't possible, if you really need a new license, with our |
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help you can ensure that the license really is a free software license |
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and avoid various practical problems. |
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</p> |
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|
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<h3 id="beyond-software">Beyond Software</h3> |
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|
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<p> |
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<a href="/philosophy/free-doc.html">Software manuals must be free</a>, |
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for the same reasons that software must be free, and because the |
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manuals are in effect part of the software. |
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</p> |
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|
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<p> |
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The same arguments also make sense for other kinds of works of |
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practical use — that is to say, works that embody useful knowledge, |
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such as educational works and reference |
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works. <a href="http://wikipedia.org">Wikipedia</a> is the best-known |
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example. |
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</p> |
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|
471 |
<p> |
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Any kind of work <em>can</em> be free, and the definition of free software |
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has been extended to a definition of <a href="http://freedomdefined.org/"> |
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free cultural works</a> applicable to any kind of works. |
475 |
</p> |
476 |
|
477 |
<h3 id="open-source">Open Source?</h3> |
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|
479 |
<p> |
480 |
Another group uses the term “open source” to mean |
481 |
something close (but not identical) to “free software”. We |
482 |
prefer the term “free software” because, once you have heard that |
483 |
it refers to freedom rather than price, it calls to mind freedom. The |
484 |
word “open” <a href="/philosophy/open-source-misses-the-point.html"> |
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never refers to freedom</a>. |
486 |
</p> |
487 |
</div> |
488 |
|
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<h3 id="History">History</h3> |
490 |
|
491 |
<p>From time to time we revise this Free Software Definition. Here is |
492 |
the list of substantive changes, along with links to show exactly what |
493 |
was changed.</p> |
494 |
|
495 |
<ul> |
496 |
|
497 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.168&r2=1.169">Version |
498 |
1.169</a>: Explain why more clearly why the four freedoms must apply |
499 |
to commercial activity. Explain why the four freedoms imply the |
500 |
freedom not to run the program and the freedom to delete it, so there |
501 |
is no need to state those as separate requirements.</li> |
502 |
|
503 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.164&r2=1.165">Version |
504 |
1.165</a>: Clarify that arbitrary annoyances in the code do not |
505 |
negate freedom 0, and that freedoms 1 and 3 enable users to remove them.</li> |
506 |
|
507 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.152&r2=1.153">Version |
508 |
1.153</a>: Clarify that freedom to run the program means nothing stops |
509 |
you from making it run.</li> |
510 |
|
511 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.140&r2=1.141">Version |
512 |
1.141</a>: Clarify which code needs to be free.</li> |
513 |
|
514 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.134&r2=1.135">Version |
515 |
1.135</a>: Say each time that freedom 0 is the freedom to run the program |
516 |
as you wish.</li> |
517 |
|
518 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.133&r2=1.134">Version |
519 |
1.134</a>: Freedom 0 is not a matter of the program's functionality.</li> |
520 |
|
521 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.130&r2=1.131">Version |
522 |
1.131</a>: A free license may not require compliance with a nonfree license |
523 |
of another program.</li> |
524 |
|
525 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.128&r2=1.129">Version |
526 |
1.129</a>: State explicitly that choice of law and choice of forum |
527 |
specifications are allowed. (This was always our policy.)</li> |
528 |
|
529 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.121&r2=1.122">Version |
530 |
1.122</a>: An export control requirement is a real problem if the |
531 |
requirement is nontrivial; otherwise it is only a potential problem.</li> |
532 |
|
533 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.117&r2=1.118">Version |
534 |
1.118</a>: Clarification: the issue is limits on your right to modify, |
535 |
not on what modifications you have made. And modifications are not limited |
536 |
to “improvements”</li> |
537 |
|
538 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.110&r2=1.111">Version |
539 |
1.111</a>: Clarify 1.77 by saying that only |
540 |
retroactive <em>restrictions</em> are unacceptable. The copyright |
541 |
holders can always grant additional <em>permission</em> for use of the |
542 |
work by releasing the work in another way in parallel.</li> |
543 |
|
544 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.104&r2=1.105">Version |
545 |
1.105</a>: Reflect, in the brief statement of freedom 1, the point |
546 |
(already stated in version 1.80) that it includes really using your modified |
547 |
version for your computing.</li> |
548 |
|
549 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.91&r2=1.92">Version |
550 |
1.92</a>: Clarify that obfuscated code does not qualify as source code.</li> |
551 |
|
552 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.89&r2=1.90">Version |
553 |
1.90</a>: Clarify that freedom 3 means the right to distribute copies |
554 |
of your own modified or improved version, not a right to participate |
555 |
in someone else's development project.</li> |
556 |
|
557 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.88&r2=1.89">Version |
558 |
1.89</a>: Freedom 3 includes the right to release modified versions as |
559 |
free software.</li> |
560 |
|
561 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.79&r2=1.80">Version |
562 |
1.80</a>: Freedom 1 must be practical, not just theoretical; |
563 |
i.e., no tivoization.</li> |
564 |
|
565 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.76&r2=1.77">Version |
566 |
1.77</a>: Clarify that all retroactive changes to the license are |
567 |
unacceptable, even if it's not described as a complete |
568 |
replacement.</li> |
569 |
|
570 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.73&r2=1.74">Version |
571 |
1.74</a>: Four clarifications of points not explicit enough, or stated |
572 |
in some places but not reflected everywhere: |
573 |
<ul> |
574 |
<li>"Improvements" does not mean the license can |
575 |
substantively limit what kinds of modified versions you can release. |
576 |
Freedom 3 includes distributing modified versions, not just changes.</li> |
577 |
<li>The right to merge in existing modules |
578 |
refers to those that are suitably licensed.</li> |
579 |
<li>Explicitly state the conclusion of the point about export controls.</li> |
580 |
<li>Imposing a license change constitutes revoking the old license.</li> |
581 |
</ul> |
582 |
</li> |
583 |
|
584 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.56&r2=1.57">Version |
585 |
1.57</a>: Add "Beyond Software" section.</li> |
586 |
|
587 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.45&r2=1.46">Version |
588 |
1.46</a>: Clarify whose purpose is significant in the freedom to run |
589 |
the program for any purpose.</li> |
590 |
|
591 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.40&r2=1.41">Version |
592 |
1.41</a>: Clarify wording about contract-based licenses.</li> |
593 |
|
594 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.39&r2=1.40">Version |
595 |
1.40</a>: Explain that a free license must allow to you use other |
596 |
available free software to create your modifications.</li> |
597 |
|
598 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.38&r2=1.39">Version |
599 |
1.39</a>: Note that it is acceptable for a license to require you to |
600 |
provide source for versions of the software you put into public |
601 |
use.</li> |
602 |
|
603 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.30&r2=1.31">Version |
604 |
1.31</a>: Note that it is acceptable for a license to require you to |
605 |
identify yourself as the author of modifications. Other minor |
606 |
clarifications throughout the text.</li> |
607 |
|
608 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.22&r2=1.23">Version |
609 |
1.23</a>: Address potential problems related to contract-based |
610 |
licenses.</li> |
611 |
|
612 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.15&r2=1.16">Version |
613 |
1.16</a>: Explain why distribution of binaries is important.</li> |
614 |
|
615 |
<li><a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&r1=1.10&r2=1.11">Version |
616 |
1.11</a>: Note that a free license may require you to send a copy of |
617 |
versions you distribute to previous developers on request.</li> |
618 |
|
619 |
</ul> |
620 |
|
621 |
<p>There are gaps in the version numbers shown above because there are |
622 |
other changes in this page that do not affect the definition or its |
623 |
interpretations. For instance, the list does not include changes in |
624 |
asides, formatting, spelling, punctuation, or other parts of the page. |
625 |
You can review the complete list of changes to the page through |
626 |
the <a href="http://web.cvs.savannah.gnu.org/viewvc/www/philosophy/free-sw.html?root=www&view=log">cvsweb |
627 |
interface</a>.</p> |
628 |
|
629 |
<h3 style="font-size:1em">Footnote</h3> |
630 |
<ol> |
631 |
<li id="f1">The reason they are numbered 0, 1, 2 and 3 is historical. Around |
632 |
1990 there were three freedoms, numbered 1, 2 and 3. Then we realized that |
633 |
the freedom to run the program needed to be mentioned explicitly. |
634 |
It was clearly more basic than the other three, so it properly should |
635 |
precede them. Rather than renumber the others, we made it freedom 0.</li> |
636 |
</ol> |
637 |
|
638 |
</div><!-- for id="content", starts in the include above --> |
639 |
<!--#include virtual="/server/footer.html" --> |
640 |
<div id="footer"> |
641 |
<div class="unprintable"> |
642 |
|
643 |
<p>Please send general FSF & GNU inquiries to |
644 |
<a href="mailto:gnu@gnu.org"><gnu@gnu.org></a>. |
645 |
There are also <a href="/contact/">other ways to contact</a> |
646 |
the FSF. Broken links and other corrections or suggestions can be sent |
647 |
to <a href="mailto:webmasters@gnu.org"><webmasters@gnu.org></a>.</p> |
648 |
|
649 |
<p><!-- TRANSLATORS: Ignore the original text in this paragraph, |
650 |
replace it with the translation of these two: |
651 |
|
652 |
We work hard and do our best to provide accurate, good quality |
653 |
translations. However, we are not exempt from imperfection. |
654 |
Please send your comments and general suggestions in this regard |
655 |
to <a href="mailto:web-translators@gnu.org"> |
656 |
<web-translators@gnu.org></a>.</p> |
657 |
|
658 |
<p>For information on coordinating and submitting translations of |
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our web pages, see <a |
660 |
href="/server/standards/README.translations.html">Translations |
661 |
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Please see the <a |
663 |
href="/server/standards/README.translations.html">Translations |
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README</a> for information on coordinating and submitting translations |
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</div> |
667 |
|
668 |
<!-- Regarding copyright, in general, standalone pages (as opposed to |
669 |
files generated as part of manuals) on the GNU web server should |
670 |
be under CC BY-ND 4.0. Please do NOT change or remove this |
671 |
without talking with the webmasters or licensing team first. |
672 |
Please make sure the copyright date is consistent with the |
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document. For web pages, it is ok to list just the latest year the |
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document was modified, or published. |
675 |
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676 |
If you wish to list earlier years, that is ok too. |
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Either "2001, 2002, 2003" or "2001-2003" are ok for specifying |
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years, as long as each year in the range is in fact a copyrightable |
679 |
year, i.e., a year in which the document was published (including |
680 |
being publicly visible on the web or in a revision control system). |
681 |
|
682 |
There is more detail about copyright years in the GNU Maintainers |
683 |
Information document, www.gnu.org/prep/maintain. --> |
684 |
|
685 |
<p>Copyright © 1996, 2002, 2004-2007, 2009-2019 |
686 |
Free Software Foundation, Inc.</p> |
687 |
|
688 |
<p>This page is licensed under a <a rel="license" |
689 |
href="http://creativecommons.org/licenses/by-nd/4.0/">Creative |
690 |
Commons Attribution-NoDerivatives 4.0 International License</a>.</p> |
691 |
|
692 |
<!--#include virtual="/server/bottom-notes.html" --> |
693 |
|
694 |
<p class="unprintable">Updated: |
695 |
<!-- timestamp start --> |
696 |
$Date: 2019/07/30 10:09:02 $ |
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699 |
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