++The free software definition presents the criteria for whether a +particular software program qualifies as free software. From time to +time we revise this definition, to clarify it or to resolve questions +about subtle issues. See the History section +below for a list of changes that affect the definition of free +software. +
+
-We maintain this free software definition to show clearly what must be -true about a particular software program for it to be considered free -software. From time to time we revise this definition to clarify it. -If you would like to review the changes we've made, please see -the History section below for more information. +“Free software” means software that respects users' +freedom and community. Roughly, it means that the users have the +freedom to run, copy, distribute, study, change and improve the +software. Thus, “free software” is a matter of +liberty, not price. To understand the concept, you should think of +“free” as in “free speech,” not as in +“free beer”.
-“Free software” is a matter of liberty, not price. To understand -the concept, you should think of “free” as in “free speech,” -not as in “free beer.” +We campaign for these freedoms because everyone deserves them. With +these freedoms, the users (both individually and collectively) control +the program and what it does for them. When users don't control the +program, we call it a “nonfree” or +“proprietary” program. The nonfree program controls the +users, and the developer controls the program; this makes the +program +an instrument of unjust power.
-Free software is a matter of the users' freedom to run, copy, distribute, -study, change and improve the software. More precisely, it means that the -program's users have the four essential freedoms: +A program is free software if the program's users have the +four essential freedoms:
-A program is free software if users have all of these freedoms. Thus, -you should be free to redistribute copies, either with or without -modifications, either gratis or charging a fee for distribution, to +A program is free software if it gives users adequately all of these +freedoms. Otherwise, it is nonfree. While we can distinguish various +nonfree distribution schemes in terms of how far they fall short of +being free, we consider them all equally unethical.
+ +The rest of this page clarifies certain points about what makes +specific freedoms adequate or not.
+ +Freedom to distribute (freedoms 2 and 3) means you are free to +redistribute copies, either with or without modifications, either +gratis or charging a fee for distribution, to anyone anywhere. Being free to do these things means (among other things) that you do not have to ask or pay for permission to do so. @@ -75,6 +103,12 @@
+The freedom to run the program as you wish means that you are not +forbidden or stopped from doing so. It has nothing to do with what +functionality the program has, or whether it is useful for what you +want to do.
+ +The freedom to redistribute copies must include binary or executable forms of the program, as well as source code, for both modified and unmodified versions. (Distributing programs in runnable form is necessary @@ -87,7 +121,7 @@
In order for freedoms 1 and 3 (the freedom to make changes and the -freedom to publish improved versions) to be meaningful, you must have +freedom to publish the changed versions) to be meaningful, you must have access to the source code of the program. Therefore, accessibility of source code is a necessary condition for free software. Obfuscated “source code” is not real source code and does not count @@ -97,12 +131,13 @@
Freedom 1 includes the freedom to use your changed version in place of the original. If the program is delivered in a product designed to -run someone else's modified versions but refuse to run yours — -a practice known as “tivoization” or (through -blacklisting) as “secure boot” — freedom 1 becomes a -theoretical fiction rather than a practical freedom. This is not -sufficient. In other words, these binaries are not free software -even if the source code they are compiled from is free. +run someone else's modified versions but refuse to run yours — a +practice known as “tivoization” or “lockdown”, +or (in its practitioners' perverse terminology) as “secure +boot” — freedom 1 becomes a theoretical fiction rather +than a practical freedom. This is not sufficient. In other words, +these binaries are not free software even if the source code they are +compiled from is free.
@@ -114,7 +149,7 @@
-Freedom 3 includes the freedom to use release your modified versions +Freedom 3 includes the freedom to release your modified versions as free software. A free license may also permit other ways of releasing them; in other words, it does not have to be a copyleft license. However, a @@ -125,9 +160,9 @@
In order for these freedoms to be real, they must be permanent and irrevocable as long as you do nothing wrong; if the developer of the -software has the power to revoke the license, or retroactively change -its terms, without your doing anything wrong to give cause, the -software is not free. +software has the power to revoke the license, or retroactively add +restrictions to its terms, without your doing anything wrong to give +cause, the software is not free.
@@ -140,7 +175,21 @@
-“Free software” does not mean “noncommercial.” A free +In the GNU project, we use +copyleft to protect the four freedoms legally for everyone. We +believe there are important reasons why +it is better to use +copyleft. However, + +noncopylefted free software is ethical +too. See Categories of Free +Software for a description of how “free software,” +“copylefted software” and other categories of software +relate to each other. +
+ ++“Free software” does not mean “noncommercial”. A free program must be available for commercial use, commercial development, and commercial distribution. Commercial development of free software is no longer unusual; such free commercial software is very important. @@ -152,41 +201,42 @@
Whether a change constitutes an improvement is a subjective matter. -If your modifications are limited, in substance, to changes that -someone else considers an improvement, that is not freedom. +If your right to modify a program is limited, in substance, to changes that +someone else considers an improvement, that program is not free.
-However, rules about how to package a modified version are acceptable, if they -don't substantively limit your freedom to release modified versions, or -your freedom to make and use modified versions privately. Rules that “if -you make your version available in this way, you must make it available in -that way also” can be acceptable too, on the same condition. (Note that -such a rule still leaves you the choice of whether to publish your version -at all.) Rules that require release of source code to the users for -versions that you put into public use are also acceptable. It is also -acceptable for the license to require that you identify -your modifications as yours, or that, if you have distributed a modified -version and a previous developer asks for a copy of it, you must send -one. +However, rules about how to package a modified version are acceptable, +if they don't substantively limit your freedom to release modified +versions, or your freedom to make and use modified versions privately. +Thus, it is acceptable for the license to require that you change the +name of the modified version, remove a logo, or identify your +modifications as yours. As long as these requirements are not so +burdensome that they effectively hamper you from releasing your +changes, they are acceptable; you're already making other changes to +the program, so you won't have trouble making a few more.
-In the GNU project, we use -“copyleft” -to protect these freedoms legally for everyone. But -non-copylefted -free software also exists. We believe there are important reasons why -it is better to use copyleft, -but if your program is non-copylefted free software, it is still basically -ethical. +Rules that “if you make your version available in this way, you +must make it available in that way also” can be acceptable too, +on the same condition. An example of such an acceptable rule is one +saying that if you have distributed a +modified version and a previous developer asks for a copy of it, you +must send one. (Note that such a rule still leaves you the choice of +whether to distribute your version at all.) Rules that require release +of source code to the users for versions that you put into public use +are also acceptable.
-See Categories of Free Software -for a description of how “free software,” “copylefted software” -and other categories of software relate to each other. -
+A special issue arises when a license requires changing the name by +which the program will be invoked from other programs. That +effectively hampers you from releasing your changed version so that it +can replace the original when invoked by those other programs. This +sort of requirement is acceptable only if there's a suitable aliasing +facility that allows you to specify the original program's name as an +alias for the modified version.Sometimes government export control regulations @@ -196,8 +246,32 @@ is refuse to impose them as conditions of use of the program. In this way, the restrictions will not affect activities and people outside the jurisdictions of these governments. Thus, free software licenses -must not require obedience to any export regulations as a condition of -any of the essential freedoms. +must not require obedience to any nontrivial export regulations as a +condition of exercising any of the essential freedoms. +
+ ++Merely mentioning the existence of export regulations, without making +them a condition of the license itself, is acceptable since it does +not restrict users. If an export regulation is actually trivial for +free software, then requiring it as a condition is not an actual +problem; however, it is a potential problem, since a later change in +export law could make the requirement nontrivial and thus render the +software nonfree. +
+ ++A free license may not require compliance with the license of a +nonfree program. Thus, for instance, if a license requires you to +comply with the licenses of “all the programs you use”, in +the case of a user that runs nonfree programs this would require +compliance with the licenses of those nonfree programs; that makes the +license nonfree. +
+ ++It is acceptable for a free license to specify which jurisdiction's +law applies, or where litigation must be done, or both.
@@ -266,7 +340,7 @@ and avoid various practical problems.
-Software manuals must be free, @@ -278,7 +352,7 @@ The same arguments also make sense for other kinds of works of practical use — that is to say, works that embody useful knowledge, such as educational works and reference -works. Wikipedia is the best known +works. Wikipedia is the best-known example.
@@ -288,26 +362,60 @@ free cultural works applicable to any kind of works. -Another group has started using the term “open source” to mean -something close (but not identical) to “free software.” We +something close (but not identical) to “free software”. We prefer the term “free software” because, once you have heard that it refers to freedom rather than price, it calls to mind freedom. The word “open” never refers to freedom.
-From time to time we revise this Free Software Definition to -clarify it. Here we provide a list of those modifications, along with -links to illustrate exactly what changed, so that others can review -them if they like.
+From time to time we revise this Free Software Definition. Here is +the list of substantive changes, along with links to show exactly what +was changed.
There are gaps in the version numbers because there are many other
-changes that do not affect the substance of the definition at all.
-Instead, they fix links, add translations, and so on. If you would
-like to review the complete list of changes, you can do so on
-our cvsweb
+ There are gaps in the version numbers shown above because there are
+other changes in this page that do not affect the definition or its
+interpretations. For instance, the list does not include changes in
+asides, formatting, spelling, punctuation, or other parts of the page.
+You can review the complete list of changes to the page through
+the cvsweb
interface.Translations of this page
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-