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whet her t his license or t he ordinary General Public License is t he bet t er st rat egy t o use in any part icular case, based on t he
explanat ions below.
When we speak of free soft ware, we are referring t o freedom of use, not price. Our General Public Licenses are designed t o m ake
sure t hat you have t he freedom t o dist ribut e copies of free soft w are ( and charge for t his service if you wish) ; t hat you receive
source code or can get it if you want it ; t hat you can change t he soft ware and use pieces of it in new free program s; and t hat you
are inform ed t hat you can do t hese t hings.
To prot ect your right s, we need t o m ake rest rict ions t hat for bid dist ribut or s t o deny you t hese right s or t o ask you t o surrender
t hese right s. These rest rict ions t ranslat e t o cert ain responsibilit ies for you if you dist ribut e copies of t he library or if you m odify i t .
For exam ple, if you dist ribut e copies of t he library, whet her grat i s or for a fee, you m ust give t he r ecipient s all t he right s t hat we
gave you. You m ust m ake sure t hat t hey , t oo, receive or can get t he source code. I f you link ot her code wit h t he library, you m u st
provide com plet e obj ect files t o t he recipient s, so t hat t hey can relink t hem wit h t he library aft er m aking changes t o t he library and
recom piling it . And you m ust show t hem t hese t erm s so t hey kn ow t heir right s.
We prot ect your right s wit h a t wo- st ep m et hod: ( 1) we copyrigh t t he library, and ( 2) we offer you t his license, which gives you
legal perm ission t o copy, dist ribut e and/ or m odify t he library .
To prot ect each dist ribut or , we want t o m ake it very clear t hat t here is no warrant y for t he free library. Also, if t he library is
m odified by som eone else and passed on, t he recipient s should know t hat what t hey have is not t he original version, so t hat t he
original aut hor's reput at ion will not be affect ed by problem s t hat m ight be int roduced by ot hers.
Finally, soft ware pat ent s pose a const ant t hreat t o t he exist ence of any free program . We wish t o m ake sure t hat a com pany
cannot effect ively rest rict t he users of a free program by obt aining a rest rict ive license from a pat ent holder. Therefore, we insist
t hat any pat ent license obt ained for a version of t he library m ust be consist ent wit h t he full freedom of use specified in t his license.
Most GNU soft ware, including som e libraries, is covered by t he ordinary GNU General Public License. This license, t he GNU Lesser
General Public License, applies t o cert ain designat ed libraries, and is quit e different from t he ordinary General Public License. We
use t his license for cert ain libraries in order t o perm it linking t hose libraries int o non- free program s.
When a program is linked wit h a library, whet her st at ically or using a shared library, t he com binat ion of t he t wo is legally speaking
a com bined wor k, a derivat ive of t he original library. The ordinary General Public License t herefore perm it s such linking only if t he
ent ire com binat ion fit s it s crit eria of freedom . The Lesser General Public License perm it s m ore lax crit eria for linking ot her code
wit h t he library.
We call t his license t he "Lesser" General Public License because it does Less t o prot ect t he user's freedom t han t he ordinary
General Public License. I t also provides ot her free soft ware developers Less of an advant age over com pet ing non- free program s.
These disadvant ages are t he reason we use t he ordinary General Public License for m any libraries. However , t he Lesser license
provides advant ages in cert ain special circum st ances.
For exam ple, on rare occasions, t here m ay be a special need t o encourage t he widest possible use of a cert ain library, so t hat it
becom es a de- fact o st andard. To achieve t his, non- free program s m ust be allowed t o use t he library. A m ore frequent case is t hat
