Version 2, June 1991
Copyright (C) 1989, 1991 Free Software Foundation, Inc. 675 MassAve, Cambridge, MA 02139, USA
Everyone is permitted to copy and distribute verbatim copies ofthis license document, but changing it is not allowed. Preamble Thelicenses for most software are designed to take away your freedom toshare and change it. By contrast, the GNU General Public License isintended to guarantee your freedom to share and change freesoftware--to make sure the software is free for all its users. ThisGeneral Public License applies to most of the Free SoftwareFoundation's software and to any other program whose authors committo using it. (Some other Free Software Foundation software is coveredby the GNU Library General Public License instead.) You can apply itto your programs, too.
When we speak of free software, we are referring to freedom, notprice. Our General Public Licenses are designed to make sure that youhave the freedom to distribute copies of free software (and chargefor this service if you wish), that you receive source code or canget it if you want it, that you can change the software or use piecesof it in new free programs; and that you know you can do thesethings.
To protect your rights, we need to make restrictions that forbidanyone to deny you these rights or to ask you to surrender therights. These restrictions translate to certain responsibilities foryou if you distribute copies of the software, or if you modify it.
For example, if you distribute copies of such a program, whethergratis or for a fee, you must give the recipients all the rights thatyou have. You must make sure that they, too, receive or can get thesource code. And you must show them these terms so they know theirrights.
We protect your rights with two steps: (1) copyright the software,and (2) offer you this license which gives you legal permission tocopy, distribute and/or modify the software.
Also, for each author's protection and ours, we want to makecertain that everyone understands that there is no warranty for thisfree software. If the software is modified by someone else and passedon, we want its recipients to know that what they have is not theoriginal, so that any problems introduced by others will not reflecton the original authors' reputations.
Finally, any free program is threatened constantly by softwarepatents. We wish to avoid the danger that redistributors of a freeprogram will individually obtain patent licenses, in effect makingthe program proprietary. To prevent this, we have made it clear thatany patent must be licensed for everyone's free use or not licensedat all.
The precise terms and conditions for copying, distribution andmodification follow. GNU GENERAL PUBLIC LICENSE TERMS AND CONDITIONSFOR COPYING, DISTRIBUTION AND MODIFICATION
0. This License applies to any program or other work whichcontains a notice placed by the copyright holder saying it may bedistributed under the terms of this General Public License. The"Program", below, refers to any such program or work, and a "workbased on the Program" means either the Program or any derivative workunder copyright law: that is to say, a work containing the Program ora portion of it, either verbatim or with modifications and/ortranslated into another language. (Hereinafter, translation isincluded without limitation in the term "modification".) Eachlicensee is addressed as "you".
Activities other than copying, distribution and modification arenot covered by this License; they are outside its scope. The act ofrunning the Program is not restricted, and the output from theProgram is covered only if its contents constitute a work based onthe Program (independent of having been made by running the Program).Whether that is true depends on what the Program does.
1. You may copy and distribute verbatim copies of the Program'ssource code as you receive it, in any medium, provided that youconspicuously and appropriately publish on each copy an appropriatecopyright notice and disclaimer of warranty; keep intact all thenotices that refer to this License and to the absence of anywarranty; and give any other recipients of the Program a copy of thisLicense along with the Program.
You may charge a fee for the physical act of transferring a copy,and you may at your option offer warranty protection in exchange fora fee.
2. You may modify your copy or copies of the Program or anyportion of it, thus forming a work based on the Program, and copy anddistribute such modifications or work under the terms of Section 1above, provided that you also meet all of these conditions:
a) You must cause the modified files to carry prominent noticesstating that you changed the files and the date of any change.
b) You must cause any work that you distribute or publish, that inwhole or in part contains or is derived from the Program or any partthereof, to be licensed as a whole at no charge to all third partiesunder the terms of this License.
c) If the modified program normally reads commands interactivelywhen run, you must cause it, when started running for suchinteractive use in the most ordinary way, to print or display anannouncement including an appropriate copyright notice and a noticethat there is no warranty (or else, saying that you provide awarranty) and that users may redistribute the program under theseconditions, and telling the user how to view a copy of this License.(Exception: if the Program itself is interactive but does notnormally print such an announcement, your work based on the Programis not required to print an announcement.) These requirements applyto the modified work as a whole. If identifiable sections of thatwork are not derived from the Program, and can be reasonablyconsidered independent and separate works in themselves, then thisLicense, and its terms, do not apply to those sections when youdistribute them as separate works. But when you distribute the samesections as part of a whole which is a work based on the Program, thedistribution of the whole must be on the terms of this License, whosepermissions for other licensees extend to the entire whole, and thusto each and every part regardless of who wrote it.
Thus, it is not the intent of this section to claim rights orcontest your rights to work written entirely by you; rather, theintent is to exercise the right to control the distribution ofderivative or collective works based on the Program.
In addition, mere aggregation of another work not based on theProgram with the Program (or with a work based on the Program) on avolume of a storage or distribution medium does not bring the otherwork under the scope of this License.
3. You may copy and distribute the Program (or a work based on it,under Section 2) in object code or executable form under the terms ofSections 1 and 2 above provided that you also do one of thefollowing:
a) Accompany it with the complete corresponding machine-readablesource code, which must be distributed under the terms of Sections 1and 2 above on a medium customarily used for software interchange;or,
b) Accompany it with a written offer, valid for at least threeyears, to give any third party, for a charge no more than your costof physically performing source distribution, a completemachine-readable copy of the corresponding source code, to bedistributed under the terms of Sections 1 and 2 above on a mediumcustomarily used for software interchange; or,
c) Accompany it with the information you received as to the offerto distribute corresponding source code. (This alternative is allowedonly for noncommercial distribution and only if you received theprogram in object code or executable form with such an offer, inaccord with Subsection b above.)
The source code for a work means the preferred form of the workfor making modifications to it. For an executable work, completesource code means all the source code for all modules it contains,plus any associated interface definition files, plus the scripts usedto control compilation and installation of the executable. However,as a special exception, the source code distributed need not includeanything that is normally distributed (in either source or binaryform) with the major components (compiler, kernel, and so on) of theoperating system on which the executable runs, unless that componentitself accompanies the executable.
If distribution of executable or object code is made by offeringaccess to copy from a designated place, then offering equivalentaccess to copy the source code from the same place counts asdistribution of the source code, even though third parties are notcompelled to copy the source along with the object code. 4. You maynot copy, modify, sublicense, or distribute the Program except asexpressly provided under this License. Any attempt otherwise to copy,modify, sublicense or distribute the Program is void, and willautomatically terminate your rights under this License. However,parties who have received copies, or rights, from you under thisLicense will not have their licenses terminated so long as suchparties remain in full compliance.
5. You are not required to accept this License, since you have notsigned it. However, nothing else grants you permission to modify ordistribute the Program or its derivative works. These actions areprohibited by law if you do not accept this License. Therefore, bymodifying or distributing the Program (or any work based on theProgram), you indicate your acceptance of this License to do so, andall its terms and conditions for copying, distributing or modifyingthe Program or works based on it.
6. Each time you redistribute the Program (or any work based onthe Program), the recipient automatically receives a license from theoriginal licensor to copy, distribute or modify the Program subjectto these terms and conditions. You may not impose any furtherrestrictions on the recipients' exercise of the rights grantedherein. You are not responsible for enforcing compliance by thirdparties to this License.
7. If, as a consequence of a court judgment or allegation ofpatent infringement or for any other reason (not limited to patentissues), conditions are imposed on you (whether by court order,agreement or otherwise) that contradict the conditions of thisLicense, they do not excuse you from the conditions of this License.If you cannot distribute so as to satisfy simultaneously yourobligations under this License and any other pertinent obligations,then as a consequence you may not distribute the Program at all. Forexample, if a patent license would not permit royalty-freeredistribution of the Program by all those who receive copiesdirectly or indirectly through you, then the only way you couldsatisfy both it and this License would be to refrain entirely fromdistribution of the Program.
If any portion of this section is held invalid or unenforceableunder any particular circumstance, the balance of the section isintended to apply and the section as a whole is intended to apply inother circumstances.
It is not the purpose of this section to induce you to infringeany patents or other property right claims or to contest validity ofany such claims; this section has the sole purpose of protecting theintegrity of the free software distribution system, which isimplemented by public license practices. Many people have madegenerous contributions to the wide range of software distributedthrough that system in reliance on consistent application of thatsystem; it is up to the author/donor to decide if he or she iswilling to distribute software through any other system and alicensee cannot impose that choice.
This section is intended to make thoroughly clear what is believedto be a consequence of the rest of this License. 8. If thedistribution and/or use of the Program is restricted in certaincountries either by patents or by copyrighted interfaces, theoriginal copyright holder who places the Program under this Licensemay add an explicit geographical distribution limitation excludingthose countries, so that distribution is permitted only in or amongcountries not thus excluded. In such case, this License incorporatesthe limitation as if written in the body of this License.
9. The Free Software Foundation may publish revised and/or newversions of the General Public License from time to time. Such newversions will be similar in spirit to the present version, but maydiffer in detail to address new problems or concerns.
Each version is given a distinguishing version number. If theProgram specifies a version number of this License which applies toit and "any later version", you have the option of following theterms and conditions either of that version or of any later versionpublished by the Free Software Foundation. If the Program does notspecify a version number of this License, you may choose any versionever published by the Free Software Foundation.
10. If you wish to incorporate parts of the Program into otherfree programs whose distribution conditions are different, write tothe author to ask for permission. For software which is copyrightedby the Free Software Foundation, write to the Free SoftwareFoundation; we sometimes make exceptions for this. Our decision willbe guided by the two goals of preserving the free status of allderivatives of our free software and of promoting the sharing andreuse of software generally.
NO WARRANTY
11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NOWARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OROTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANYKIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THEIMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULARPURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THEPROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUMETHE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO INWRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFYAND/OR REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOUFOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL ORCONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THEPROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEINGRENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR AFAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IFSUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OFSUCH DAMAGES.
END OF TERMS AND CONDITIONS Appendix: How to Apply These Terms toYour New Programs
If you develop a new program, and you want it to be of thegreatest possible use to the public, the best way to achieve this isto make it free software which everyone can redistribute and changeunder these terms.
To do so, attach the following notices to the program. It issafest to attach them to the start of each source file to mosteffectively convey the exclusion of warranty; and each file shouldhave at least the "copyright" line and a pointer to where the fullnotice is found.
This program is free software; you can redistribute it and/ormodify it under the terms of the GNU General Public License aspublished by the Free Software Foundation; either version 2 of theLicense, or (at your option) any later version.
This program is distributed in the hope that it will be useful,but WITHOUT ANY WARRANTY; without even the implied warranty ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNUGeneral Public License for more details.
You should have received a copy of the GNU General Public Licensealong with this program; if not, write to the Free SoftwareFoundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
Also add information on how to contact you by electronic and papermail.
If the program is interactive, make it output a short notice likethis when it starts in an interactive mode:
Gnomovision version 69, Copyright (C) 19yy name of authorGnomovision comes with ABSOLUTELY NO WARRANTY; for details type `showw'. This is free software, and you are welcome to redistribute itunder certain conditions; type `show c' for details.
The hypothetical commands `show w' and `show c' should show theappropriate parts of the General Public License. Of course, thecommands you use may be called something other than `show w' and`show c'; they could even be mouse-clicks or menu items--whateversuits your program.
You should also get your employer (if you work as a programmer) oryour school, if any, to sign a "copyright disclaimer" for theprogram, if necessary. Here is a sample; alter the names:
Yoyodyne, Inc., hereby disclaims all copyright interest in theprogram `Gnomovision' (which makes passes at compilers) written byJames Hacker.
This General Public License does not permit incorporating yourprogram into proprietary programs. If your program is a subroutinelibrary, you may consider it more useful to permit linkingproprietary applications with the library. If this is what you wantto do, use the GNU Library General Public License instead of thisLicense.
; ;