2
To protect your r ights, we ne ed to make r estriction s that forbi d anyone to de ny you these rights or to ask you
to surrender the rights . These res trictions translate to certain r esponsibiliti es for you if you distrib ute copies of
the software, or i f you modify it.
For example, if you distribute co pies of such a prog ram, whethe r gratis or for a fee, you must giv e the recipient s
all the r ights tha t you have . You must make sur e that they, too, receive or can get the sou rce code. And you
must show them these te rms so they know the ir rights.
We protect your rig hts with two s teps: (1) copyright t he software , and (2) offer yo u this license whi ch gives you
legal permission to co py, distribute and /or modify the soft ware.
Also, for each au thor’s pr otection and our s, we want to make ce rtain that ever yone un derstan ds that there
is no warr anty for this free software . If the softwar e is modi ed by som eone else and passed on, we want its
recipients to know tha t what th ey have is not the original, so that a ny problems introduced by others will not
reect on the origi nal authors’ rep utations.
Finally, any f ree pr ogram is t hreaten ed con stantl y by softw are pa tents. We w ish to avoid the danger that
redistributor s of a free progr am will individua lly obtain paten t licenses, in effe ct making the pr ogram propri etary.
To prevent this, we have made it cl ear that any patent mu st be licensed for eve ryone’s free use or n ot licensed at
all.
The precise terms an d conditions for copying , distributi on and modicatio n follow.
GNU GENERAL PU BLIC LICENSE
TERMS AND CONDIT IONS FOR COPYING , DISTRIBU TION AND MODIFI CATION
0. This License appl ies to any program or other work which conta ins a notice placed by t he copyright holder
saying it may be dis tributed unde r the terms of t his General P ublic License. T he “Program”, be low, refers to
any such program or wo rk, and a “work based on the Progr am” means eithe r the Program or a ny derivative
work under co pyright law: that is to say, a work containing the Program or a por tion of i t, either verbatim
or with mod ications an d/or transla ted into an other langua ge. (Herei nafter, trans lation is included wit hout
limitation in the ter m “modication”.) Each l icensee is addresse d as “you”.
Activities othe r than copying, dis tribution an d modication ar e not covered by this License; they are outside
its scope. The act of ru nning the Progra m is not restrict ed, and the output f rom the Program is cove red only
if its conte nts constit ute a wor k based on the Prog ram (indep endent of having been made by r unning the
Program). Whether th at is true depends o n what the Progra m does.
1. You may copy and d istribute ve rbatim copies of th e Program’s source co de as you receive it , in any medium,
provided th at you co nspicuously and app ropriately publish on each copy an appropria te copyrig ht notice
and disclaimer of warr anty; kee p intact all the notices that refer to this Licen se and to the absen ce of any
warranty; and g ive any other recipie nts of the Progra m a copy of this License along w ith the Program .
You may charge a fee for the physica l act of tr ansferring a copy, and you may at your option offer warr anty
protection in exchan ge for a fee.
2. You may modify your copy or copies of the Program o r any por tion of it, thu s forming a work based on the
Program, and copy and distribute such modications or work under the terms of Section 1 above, provided that
you also meet all of these cond itions:
a) You must ca use the modied les to carr y prominent notices statin g that you change d the les and the
date of any change.
b) You must caus e any work t hat you distr ibute or pu blish, that in whole or in part con tains or is derived
from the Progr am or any par t thereof, t o be licensed a s a whole at n o charge to al l third par ties under
the terms of this Licens e.
c) If the modi ed prog ram nor mally r eads comm ands int eractivel y when run, you must cause it, wh en
started r unning for such interactiv e use in the most ordinar y way, to prin t or display a n announcement
including an approp riate copyright notice and a notice t hat there is no wa rranty (or else , saying that you
provide a warrant y) and t hat user s may re distribu te the program under the se condit ions, and telling
the user how to vi ew a copy of this L icense. (Except ion: if the Pro gram itself is interacti ve but does not
normally pr int such a n announceme nt, your work based on the Program is not re quired to print an
announcement.)
These requir ements appl y to the modif ied wo rk a s a whole. If identi fiabl e sec tions of th at wo rk ar e
not der ived f rom th e Prog ram, a nd ca n be reasona bly con sidered indep endent and s eparate work s in
themselves, then this License, and it s terms, do not apply to those se ctions wh en you d istribute them a s
separate works . But when you di stribute the same sections a s part of a whol e which is a work ba sed on the
Program, the distribu tion of the whole mus t be on t he terms of this Licen se, whose p ermissions for other
licensees extend to t he entire whole, a nd thus to each and ever y part regar dless of who wrote it .