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GNU GENERAL PUBLIC LICENSE
Version2,June1991
Copyright(C)1989,1991FreeSoftwareFoundation,Inc.,51FranklinStreet,FifthFloor,Boston,MA
02110-1301USAEveryoneispermittedtocopyanddistributeverbatimcopiesofthislicensedocument,
but changing it is not allowed.
Preamble
Thelicensesformostsoftwarearedesignedtotakeawayyourfreedomtoshareandchangeit.By
contrast,theGNUGeneralPublicLicenseisintendedtoguaranteeyourfreedomtoshareandchange
freesoftware--tomakesurethesoftwareisfreeforallitsusers.ThisGeneralPublicLicenseapplies
tomostoftheFreeSoftwareFoundation'ssoftwareandtoanyotherprogramwhoseauthorscommit
tousingit.(SomeotherFreeSoftwareFoundationsoftwareiscoveredbytheGNULesserGeneral
PublicLicenseinstead.)Youcanapplyittoyourprograms,too.
Whenwespeakoffreesoftware,wearereferringtofreedom,notprice.OurGeneralPublicLicenses
are designed to make sure that you have the freedom to distribute copies of free software (and charge
for this service if you wish), that you receive source code or can get it if you want it, that you can change
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
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
mustmakesurethatthey,too,receiveorcangetthesourcecode.Andyoumustshowthemthese
terms so they know their rights.
Weprotectyourrightswithtwosteps:(1)copyrightthesoftware,and(2)offeryouthislicensewhich
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, 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.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
Programoranyderivativeworkundercopyrightlaw:thatistosay,aworkcontainingtheProgramora
portionofit,eitherverbatimorwithmodificationsand/ortranslatedintoanotherlanguage.(Hereinafter,
translationisincludedwithoutlimitationintheterm"modification".)Eachlicenseeisaddressedas"you".
Activitiesotherthancopying,distributionandmodificationarenotcoveredbythisLicense;theyare
outsideitsscope.TheactofrunningtheProgramisnotrestricted,andtheoutputfromtheProgram
iscoveredonlyifitscontentsconstituteaworkbasedontheProgram(independentofhavingbeen
madebyrunningtheProgram).WhetherthatistruedependsonwhattheProgramdoes.