Specifications



GNUGENERALPUBLICLICENSE

Version3,29June2007



Everyoneispermittedtocopyanddistributeverbatimcopiesofthislicensedocument,but

changingitisnotallowed.



Preamble

TheGNUGeneralPublicLicenseisafree,copyleftlicenseforsoftwareandotherkindsof

works.



Thelicensesformostsoftwareandotherpracticalworksaredesignedtotakeawayyour

freedomtoshareandchangetheworks.Bycontrast,theGNUGeneralPublicLicenseis

intendedtoguaranteeyourfreedomtoshareandchangeallversionsofaprogram‐‐to

makesureitremainsfreesoftwareforallitsusers.We,theFreeSoftwareFoundation,use

theGNUGeneralPublicLicenseformostofoursoftware;itappliesalsotoanyotherwork

releasedthiswaybyitsauthors.Youcanapplyittoyourprograms,too.



Whenwespeakoffreesoftware,wearereferringtofreedom,notprice.OurGeneral

PublicLicensesaredesignedtomakesurethatyouhavethefreedomtodistributecopies

offreesoftware(andchargeforthem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preventothersfromdenyingyoutheserightsorasking

youtosurrendertherights.Therefore,youhavecertainresponsibilitiesifyoudistribute

copiesofthesoftware,orifyoumodifyit:responsibilitiestorespectthefreedomof

others.



Forexample,ifyoudistributecopiesofsuchaprogram,whethergratisorforafee,you

mustpassontotherecipientsthesamefreedomsthatyoureceived.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.



 166