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Version 2, June 1991
&RS\ULJKW&)UHH6RIWZDUH)RXQGDWLRQ,QF7HPSOH3ODFH6XLWH%RVWRQ0$ USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.
Preamble
The licenses for most software are designed to take away your freedom to share and change it. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change free software-
When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are GHVLJQHGWRPDNHVXUHWKDW\RXKDYHWKHIUHHGRPWRGLVWULEXWHFRSLHVRIIUHHVRIWZDUHDQGFKDUJHIRUWKLV VHUYLFHLI\RXZLVKWKDW\RXUHFHLYHVRXUFHFRGHRUFDQJHWLWLI\RXZDQWLWWKDW\RXFDQFKDQJHWKHVRIWZDUH RUXVHSLHFHVRILWLQQHZIUHHSURJUDPVDQGWKDW\RXNQRZ\RXFDQGRWKHVHWKLQJV
To protect your rights, we need to make restrictions that forbid anyone to deny you these rights or to ask you to surrender the rights. These restrictions translate to certain responsibilities for you if you distribute copies of the software, or if you modify it.
For example, if you distribute copies of such a program, whether gratis or for a fee, you must give the recipients all the rights that you have. You must make sure that they, too, receive or can get the source code. And you must show them these terms so they know their rights.
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Also, for each author’s protection and ours, we want to make certain that everyone understands that there LVQRZDUUDQW\IRUWKLVIUHHVRIWZDUH,IWKHVRIWZDUHLVPRGLÀHGE\VRPHRQHHOVHDQGSDVVHGRQZHZDQWLWV recipients to know that what they have is not the original, so that any problems introduced by others will not
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Finally, any free program is threatened constantly by software patents. We wish to avoid the danger that redistributors of a free program will individually obtain patent licenses, in effect making the program proprietary. To prevent this, we have made it clear that any patent must be licensed for everyone’s free use or not licensed at all.
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TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
0.This License applies to any program or other work which contains a notice placed by the copyright holder saying it may be distributed under the terms of this General Public License. The “Program”, below, refers to any such program or work, and a “work based on the Program” means either the Program or any derivative work under copyright law: that is to say, a work containing the Program or a portion of it, either
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$FWLYLWLHVRWKHUWKDQFRS\LQJGLVWULEXWLRQDQGPRGLÀFDWLRQDUHQRWFRYHUHGE\WKLV/LFHQVHWKH\DUHRXWVLGHLWV scope. The act of running the Program is not restricted, and the output from the Program is covered only if its contents constitute a work based on the
3URJUDPLQGHSHQGHQWRIKDYLQJEHHQPDGHE\UXQQLQJWKH3URJUDP:KHWKHUWKDWLVWUXHGHSHQGVRQ what the Program does.