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GNU GENERAL PUBLIC LICENSE
Version 2, June 1991
Copyright(C)1989,1991FreeSoftwareFoundation,Inc.,51FranklinStreet,FifthFloor,Boston,MA
02110-1301USAEveryoneispermittedtocopyanddistributeverbatimcopiesofthislicensedocument,
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,theGNUGeneralPublicLicenseisintendedtoguaranteeyourfreedomtoshareandchange
free software--to make sure the software is free for all its users. This General Public License applies
tomostoftheFreeSoftwareFoundation'ssoftwareandtoanyotherprogramwhoseauthorscommit
tousingit.(SomeotherFreeSoftwareFoundationsoftwareiscoveredbytheGNULesserGeneral
Public License instead.) You can apply it to your programs, too.
Whenwespeakoffreesoftware,wearereferringtofreedom,notprice.OurGeneralPublicLicenses
are designed to make sure that you have the freedom to distribute copies of free software (and charge
the software or use pieces of it in new free programs; and that you know you can do these things.
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
youdistributecopiesofthesoftware,orifyoumodifyit.Forexample,ifyoudistributecopiesofsuch
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.
We protect your rights with two steps: (1) copyright the software, and (2) offer you this license which
givesyoulegalpermissiontocopy,distributeand/ormodifythesoftware.
Also,foreachauthor'sprotectionandours,wewanttomakecertainthateveryoneunderstandsthat
there 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 introduced
byotherswillnotreflectontheoriginalauthors'reputations.
Finally,anyfreeprogramisthreatenedconstantlybysoftwarepatents.Wewishtoavoidthedangerthat
redistributors of a free program will individually obtain patent licenses, in effect making the program
proprietary.Topreventthis,wehavemadeitclearthatanypatentmustbelicensedforeveryone's
free use or not licensed at all.
The precise terms and conditions for copying, distribution and modification follow.
GNU GENERAL PUBLIC LICENSE
TERMSANDCONDITIONSFORCOPYING,DISTRIBUTIONANDMODIFICATION
0.This License applies to any program or other work which contains a notice placed by the copyright
holdersayingitmaybedistributedunderthetermsofthisGeneralPublicLicense.The"Program",
below,referstoanysuchprogramorwork,anda"workbasedontheProgram"meanseitherthe
Program or any derivative work under copyright law: that is to say, a work containing the Program or a
portionofit,eitherverbatimorwithmodificationsand/ortranslatedintoanotherlanguage.(Hereinafter,
translationisincludedwithoutlimitationintheterm"modification".)Eachlicenseeisaddressedas"you".
Activities other than copying, distribution and modification are not covered by this License; they are
outside its scope. The act of running the Program is not restricted, and the output from the