Trademark and License Information 87
GNU General Public License
Version 2, June 1991
Copyright(C)1989,1991 FreeSoftwareFoundation,Inc.
675MassAve,Cambridge,MA02139,USA
Everyoneispermittedtocopyanddistributeverbatimcopiesofthislicensedocument,butchangingitisnotallowed.
Preamble
Thelicensesformostsoftwarearedesignedtotakeawayyourfreedomtoshareandchangeit.Bycontrast,theGNUGeneralPublicLicenseisintendedto
guaranteeyourfreedomtoshareandchangefreesoftware--tomakesurethesoftwareisfreeforallitsusers.ThisGeneralPublicLicenseappliestomostofthe
FreeSoftwareFoundation’ssoftwareandtoanyotherprogramwhoseauthorscommittousingit.(SomeotherFreeSoftwareFoundationsoftwareiscoveredby
theGNULibraryGeneralPublicLicenseinstead.)Youcanapplyittoyourprograms,too.
Whenwespeakoffreesoftware,wearereferringtofreedom,notprice.OurGeneralPublicLicensesaredesignedtomakesurethatyouhavethefreedomtodis-
tributecopiesoffreesoftware(andchargeforthisserviceifyouwish),thatyoureceivesourcecodeorcangetitifyouwantit,thatyoucanchangethesoftware
orusepiecesofitinnewfreeprograms;andthatyouknowyoucandothesethings.
Toprotectyourrights,weneedtomakerestrictionsthatforbidanyonetodenyyoutheserightsortoaskyoutosurrendertherights.Theserestrictionstranslate
tocertainresponsibilitiesforyouifyoudistributecopiesofthesoftware,orifyoumodifyit.
Forexample,ifyoudistributecopiesofsuchaprogram,whethergratisorforafee,youmustgivetherecipientsalltherightsthatyouhave.Youmustmakesure
thatthey,too,receiveorcangetthesourcecode.Andyoumustshowthemthesetermssotheyknowtheirrights.
Weprotectyourrightswithtwosteps:(1)copyrightthesoftware,and(2)offeryouthislicensewhichgivesyoulegalpermissiontocopy,distributeand/ormodify
thesoftware.
Also,foreachauthor’sprotectionandours,wewanttomakecertainthateveryoneunderstandsthatthereisnowarrantyforthisfreesoftware.Ifthesoftwareis
modifiedbysomeoneelseandpassedon,wewantitsrecipientstoknowthatwhattheyhaveisnottheoriginal,sothatanyproblemsintroducedbyotherswill
notreflectontheoriginalauthors’reputations.
Finally,anyfreeprogramisthreatenedconstantlybysoftwarepatents.Wewishtoavoidthedangerthatredistributorsofafreeprogramwillindividuallyobtain
patentlicenses,ineffectmakingtheprogramproprietary.Topreventthis,wehavemadeitclearthatanypatentmustbelicensedforeveryone’sfreeuseornot
licensedatall.
Theprecisetermsandconditionsforcopying,distributionandmodicationfollow.
GNU GENERAL PUBLIC LICENSE
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
0.ThisLicenseappliestoanyprogramorotherworkwhichcontainsanoticeplacedbythecopyrightholdersayingitmaybedistributedunderthetermsofthis
GeneralPublicLicense.The“Program”,below,referstoanysuchprogramorwork,anda“workbasedontheProgram”meanseithertheProgramoranyderiva-
tiveworkundercopyrightlaw:thatistosay,aworkcontainingtheProgramoraportionofit,eitherverbatimorwithmodificationsand/ortranslatedintoanother
language.(Hereinafter,translationisincludedwithoutlimitationintheterm“modification”.)Eachlicenseeisaddressedas“you”.
Activitiesotherthancopying,distributionandmodificationarenotcoveredbythisLicense;theyareoutsideitsscope.TheactofrunningtheProgramisnot
restricted,andtheoutputfromtheProgramiscoveredonlyifitscontentsconstituteaworkbasedontheProgram(independentofhavingbeenmadebyrunning
theProgram).WhetherthatistruedependsonwhattheProgramdoes.
1.YoumaycopyanddistributeverbatimcopiesoftheProgram’ssourcecodeasyoureceiveit,inanymedium,providedthatyouconspicuouslyandappropri-
atelypublishoneachcopyanappropriatecopyrightnoticeanddisclaimerofwarranty;keepintactallthenoticesthatrefertothisLicenseandtotheabsenceof
anywarranty;andgiveanyotherrecipientsoftheProgramacopyofthisLicensealongwiththeProgram.
Youmaychargeafeeforthephysicalactoftransferringacopy,andyoumayatyouroptionofferwarrantyprotectioninexchangeforafee.
2.YoumaymodifyyourcopyorcopiesoftheProgramoranyportionofit,thusformingaworkbasedontheProgram,andcopyanddistributesuchmodifica-
tionsorworkunderthetermsofSection1above,providedthatyoualsomeetalloftheseconditions:
a)Youmustcausethemodifiedfilestocarryprominentnoticesstatingthatyouchangedthefilesandthedateofanychange.
b)Youmustcauseanyworkthatyoudistributeorpublish,thatinwholeorinpartcontainsorisderivedfromtheProgramoranypartthereof,tobelicensed
asawholeatnochargetoallthirdpartiesunderthetermsofthisLicense.
c)Ifthemodifiedprogramnormallyreadscommandsinteractivelywhenrun,youmustcauseit,whenstartedrunningforsuchinteractiveuseinthe
mostordinaryway,toprintordisplayanannouncementincludinganappropriatecopyrightnoticeandanoticethatthereisnowarranty(orelse,saying
thatyouprovideawarranty)andthatusersmayredistributetheprogramundertheseconditions,andtellingtheuserhowtoviewacopyofthisLicense.
(Exception:iftheProgramitselfisinteractivebutdoesnotnormallyprintsuchanannouncement,yourworkbasedontheProgramisnotrequiredtoprint
anannouncement.)
Theserequirementsapplytothemodifiedworkasawhole.IfidentifiablesectionsofthatworkarenotderivedfromtheProgram,andcanbereasonablyconsid-
eredindependentandseparateworksinthemselves,thenthisLicense,anditsterms,donotapplytothosesectionswhenyoudistributethemasseparateworks.
ButwhenyoudistributethesamesectionsaspartofawholewhichisaworkbasedontheProgram,thedistributionofthewholemustbeonthetermsofthis
License,whosepermissionsforotherlicenseesextendtotheentirewhole,andthustoeachandeverypartregardlessofwhowroteit.
Thus,itisnottheintentofthissectiontoclaimrightsorcontestyourrightstoworkwrittenentirelybyyou;rather,theintentistoexercisetherighttocontrolthe
distributionofderivativeorcollectiveworksbasedontheProgram.
Inaddition,mereaggregationofanotherworknotbasedontheProgramwiththeProgram(orwithaworkbasedontheProgram)onavolumeofastorageor
distributionmediumdoesnotbringtheotherworkunderthescopeofthisLicense.
3.YoumaycopyanddistributetheProgram(oraworkbasedonit,underSection2)inobjectcodeorexecutableformunderthetermsofSections1and2above
providedthatyoualsodooneofthefollowing: