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The Free Software Definition 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. 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 the users' freedom to run, copy, distribute, study, change and improve the software. More precisely, it refers to four kinds of freedom, for the users of the software: * The freedom to run the program, for any purpose (freedom 0). * The freedom to study how the program works, and adapt it to your needs (freedom 1). Access to the source code is a precondition for this. * The freedom to redistribute copies so you can help your neighbor (freedom 2). * The freedom to improve the program, and release your improvements to the public, so that the whole community benefits (freedom 3). Access to the source code is a precondition for this. 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 anyone anywhere. Being free to do these things means (among other things) that you do not have to ask or pay for permission.