Appendix F.GNU GENERAL PUBLIC LICENSEVersion 2, June 1991Copyright © 1989, 1991 Free Software Foundation, Inc.59 Temple Place - Suite 330, Boston, MA 02111-1307, USAEveryone is permitted to copy and distribute verbatim copiesof this license document, but changing it is not allowed.F.1. PreambleThe licenses for most software are designed to take away your freedom to share and change it. Bycontrast, the GNU General Public License is intended to guarantee your freedom to share and changefree software--to make sure the software is free for all its users. This General Public License appliesto most of the Free Software Foundation’s software and to any other program whose authors committo using it. (Some other Free Software Foundation software is covered by the GNU Library GeneralPublic License instead.) You can apply it to your programs, too.When we speak of free software, we are referring to freedom, not price. Our General Public Licensesare designed to make sure that you have the freedom to distribute copies of free software (and chargefor this service if you wish), that you receive source code or can get it if you want it, that you canchange the software or use pieces of it in new free programs; and that you know you can do thesethings.To protect your rights, we need to make restrictions that forbid anyone to deny you these rights or toask you to surrender the rights. These restrictions translate to certain responsibilities for you if youdistribute 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 therecipients all the rights that you have. You must make sure that they, too, receive or can get the sourcecode. And you must show them these terms so they know their rights.We protect your rights with two steps: (1) copyright the software, and (2) offer you this license whichgives you legal permission to copy, distribute and/or modify the software.Also, for each author’s protection and ours, we want to make certain that everyone understands thatthere is no warranty for this free software. If the software is modified by someone else and passed on,we want its recipients to know that what they have is not the original, so that any problems introducedby others will not reflect on the original authors’ reputations.Finally, any free program is threatened constantly by software patents. We wish to avoid the dangerthat redistributors of a free program will individually obtain patent licenses, in effect making theprogram proprietary. To prevent this, we have made it clear that any patent must be licensed foreveryone’s free use or not licensed at all.The precise terms and conditions for copying, distribution and modification follow.TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION1. This License applies to any program or other work which contains a notice placed by the copy-right 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"
