User's Manual

140
GNU GENERAL PUBLIC LICENSE
Version 2, June 1991
Copyright(C)1989,1991FreeSoftwareFoundation,Inc.
59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Everyoneispermittedtocopyanddistributeverbatimcopiesof
this license document, 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,theGNUGeneral
PublicLicenseisintendedtoguaranteeyourfreedomtoshare
andchangefreesoftware--tomakesurethesoftwareisfreeforall
itsusers.ThisGeneralPublicLicenseappliestomostoftheFree
SoftwareFoundation’ssoftwareandtoanyotherprogramwhose
authorscommittousingit.(SomeotherFreeSoftwareFoundation
softwareiscoveredbytheGNULibraryGeneralPublic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 Licenses 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 must make sure that they, too, receive or can get
the source code. And you must show them these terms so they