1GNU GENERAL PUBLIC LICENSE 2 3Version 2, June 1991 4 5Copyright (C) 1989, 1991 Free Software Foundation, Inc. 6 751 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA 8 9Everyone is permitted to copy and distribute verbatim copies of this license 10document, but changing it is not allowed. 11 12Preamble 13 14The licenses for most software are designed to take away your freedom to share 15and change it. By contrast, the GNU General Public License is intended to 16guarantee your freedom to share and change free software--to make sure the 17software is free for all its users. This General Public License applies to 18most of the Free Software Foundation's software and to any other program whose 19authors commit to using it. (Some other Free Software Foundation software 20is covered by the GNU Lesser General Public License instead.) You can apply 21it to your programs, too. 22 23When we speak of free software, we are referring to freedom, not price. Our 24General Public Licenses are designed to make sure that you have the freedom 25to distribute copies of free software (and charge for this service if you 26wish), that you receive source code or can get it if you want it, that you 27can change the software or use pieces of it in new free programs; and that 28you know you can do these things. 29 30To protect your rights, we need to make restrictions that forbid anyone to 31deny you these rights or to ask you to surrender the rights. These restrictions 32translate to certain responsibilities for you if you distribute copies of 33the software, or if you modify it. 34 35For example, if you distribute copies of such a program, whether gratis or 36for a fee, you must give the recipients all the rights that you have. You 37must make sure that they, too, receive or can get the source code. And you 38must show them these terms so they know their rights. 39 40We protect your rights with two steps: (1) copyright the software, and (2) 41offer you this license which gives you legal permission to copy, distribute 42and/or modify the software. 43 44Also, for each author's protection and ours, we want to make certain that 45everyone understands that there is no warranty for this free software. If 46the software is modified by someone else and passed on, we want its recipients 47to know that what they have is not the original, so that any problems introduced 48by others will not reflect on the original authors' reputations. 49 50Finally, any free program is threatened constantly by software patents. We 51wish to avoid the danger that redistributors of a free program will individually 52obtain patent licenses, in effect making the program proprietary. To prevent 53this, we have made it clear that any patent must be licensed for everyone's 54free use or not licensed at all. 55 56The precise terms and conditions for copying, distribution and modification 57follow. 58 59TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 60 610. This License applies to any program or other work which contains a notice 62placed by the copyright holder saying it may be distributed under the terms 63of this General Public License. The "Program", below, refers to any such program 64or work, and a "work based on the Program" means either the Program or any 65derivative work under copyright law: that is to say, a work containing the 66Program or a portion of it, either verbatim or with modifications and/or translated 67into another language. (Hereinafter, translation is included without limitation 68in the term "modification".) Each licensee is addressed as "you". 69 70Activities other than copying, distribution and modification are not covered 71by this License; they are outside its scope. The act of running the Program 72is not restricted, and the output from the Program is covered only if its 73contents constitute a work based on the Program (independent of having been 74made by running the Program). Whether that is true depends on what the Program 75does. 76 771. You may copy and distribute verbatim copies of the Program's source code 78as you receive it, in any medium, provided that you conspicuously and appropriately 79publish on each copy an appropriate copyright notice and disclaimer of warranty; 80keep intact all the notices that refer to this License and to the absence 81of any warranty; and give any other recipients of the Program a copy of this 82License along with the Program. 83 84You may charge a fee for the physical act of transferring a copy, and you 85may at your option offer warranty protection in exchange for a fee. 86 872. You may modify your copy or copies of the Program or any portion of it, 88thus forming a work based on the Program, and copy and distribute such modifications 89or work under the terms of Section 1 above, provided that you also meet all 90of these conditions: 91 92a) You must cause the modified files to carry prominent notices stating that 93you changed the files and the date of any change. 94 95b) You must cause any work that you distribute or publish, that in whole or 96in part contains or is derived from the Program or any part thereof, to be 97licensed as a whole at no charge to all third parties under the terms of this 98License. 99 100c) If the modified program normally reads commands interactively when run, 101you must cause it, when started running for such interactive use in the most 102ordinary way, to print or display an announcement including an appropriate 103copyright notice and a notice that there is no warranty (or else, saying that 104you provide a warranty) and that users may redistribute the program under 105these conditions, and telling the user how to view a copy of this License. 106(Exception: if the Program itself is interactive but does not normally print 107such an announcement, your work based on the Program is not required to print 108an announcement.) 109 110These requirements apply to the modified work as a whole. If identifiable 111sections of that work are not derived from the Program, and can be reasonably 112considered independent and separate works in themselves, then this License, 113and its terms, do not apply to those sections when you distribute them as 114separate works. But when you distribute the same sections as part of a whole 115which is a work based on the Program, the distribution of the whole must be 116on the terms of this License, whose permissions for other licensees extend 117to the entire whole, and thus to each and every part regardless of who wrote 118it. 119 120Thus, it is not the intent of this section to claim rights or contest your 121rights to work written entirely by you; rather, the intent is to exercise 122the right to control the distribution of derivative or collective works based 123on the Program. 124 125In addition, mere aggregation of another work not based on the Program with 126the Program (or with a work based on the Program) on a volume of a storage 127or distribution medium does not bring the other work under the scope of this 128License. 129 1303. You may copy and distribute the Program (or a work based on it, under Section 1312) in object code or executable form under the terms of Sections 1 and 2 above 132provided that you also do one of the following: 133 134a) Accompany it with the complete corresponding machine-readable source code, 135which must be distributed under the terms of Sections 1 and 2 above on a medium 136customarily used for software interchange; or, 137 138b) Accompany it with a written offer, valid for at least three years, to give 139any third party, for a charge no more than your cost of physically performing 140source distribution, a complete machine-readable copy of the corresponding 141source code, to be distributed under the terms of Sections 1 and 2 above on 142a medium customarily used for software interchange; or, 143 144c) Accompany it with the information you received as to the offer to distribute 145corresponding source code. (This alternative is allowed only for noncommercial 146distribution and only if you received the program in object code or executable 147form with such an offer, in accord with Subsection b above.) 148 149The source code for a work means the preferred form of the work for making 150modifications to it. For an executable work, complete source code means all 151the source code for all modules it contains, plus any associated interface 152definition files, plus the scripts used to control compilation and installation 153of the executable. However, as a special exception, the source code distributed 154need not include anything that is normally distributed (in either source or 155binary form) with the major components (compiler, kernel, and so on) of the 156operating system on which the executable runs, unless that component itself 157accompanies the executable. 158 159If distribution of executable or object code is made by offering access to 160copy from a designated place, then offering equivalent access to copy the 161source code from the same place counts as distribution of the source code, 162even though third parties are not compelled to copy the source along with 163the object code. 164 1654. You may not copy, modify, sublicense, or distribute the Program except 166as expressly provided under this License. Any attempt otherwise to copy, modify, 167sublicense or distribute the Program is void, and will automatically terminate 168your rights under this License. However, parties who have received copies, 169or rights, from you under this License will not have their licenses terminated 170so long as such parties remain in full compliance. 171 1725. You are not required to accept this License, since you have not signed 173it. However, nothing else grants you permission to modify or distribute the 174Program or its derivative works. These actions are prohibited by law if you 175do not accept this License. Therefore, by modifying or distributing the Program 176(or any work based on the Program), you indicate your acceptance of this License 177to do so, and all its terms and conditions for copying, distributing or modifying 178the Program or works based on it. 179 1806. Each time you redistribute the Program (or any work based on the Program), 181the recipient automatically receives a license from the original licensor 182to copy, distribute or modify the Program subject to these terms and conditions. 183You may not impose any further restrictions on the recipients' exercise of 184the rights granted herein. You are not responsible for enforcing compliance 185by third parties to this License. 186 1877. If, as a consequence of a court judgment or allegation of patent infringement 188or for any other reason (not limited to patent issues), conditions are imposed 189on you (whether by court order, agreement or otherwise) that contradict the 190conditions of this License, they do not excuse you from the conditions of 191this License. If you cannot distribute so as to satisfy simultaneously your 192obligations under this License and any other pertinent obligations, then as 193a consequence you may not distribute the Program at all. For example, if a 194patent license would not permit royalty-free redistribution of the Program 195by all those who receive copies directly or indirectly through you, then the 196only way you could satisfy both it and this License would be to refrain entirely 197from distribution of the Program. 198 199If any portion of this section is held invalid or unenforceable under any 200particular circumstance, the balance of the section is intended to apply and 201the section as a whole is intended to apply in other circumstances. 202 203It is not the purpose of this section to induce you to infringe any patents 204or other property right claims or to contest validity of any such claims; 205this section has the sole purpose of protecting the integrity of the free 206software distribution system, which is implemented by public license practices. 207Many people have made generous contributions to the wide range of software 208distributed through that system in reliance on consistent application of that 209system; it is up to the author/donor to decide if he or she is willing to 210distribute software through any other system and a licensee cannot impose 211that choice. 212 213This section is intended to make thoroughly clear what is believed to be a 214consequence of the rest of this License. 215 2168. If the distribution and/or use of the Program is restricted in certain 217countries either by patents or by copyrighted interfaces, the original copyright 218holder who places the Program under this License may add an explicit geographical 219distribution limitation excluding those countries, so that distribution is 220permitted only in or among countries not thus excluded. In such case, this 221License incorporates the limitation as if written in the body of this License. 222 2239. The Free Software Foundation may publish revised and/or new versions of 224the General Public License from time to time. Such new versions will be similar 225in spirit to the present version, but may differ in detail to address new 226problems or concerns. 227 228Each version is given a distinguishing version number. If the Program specifies 229a version number of this License which applies to it and "any later version", 230you have the option of following the terms and conditions either of that version 231or of any later version published by the Free Software Foundation. If the 232Program does not specify a version number of this License, you may choose 233any version ever published by the Free Software Foundation. 234 23510. If you wish to incorporate parts of the Program into other free programs 236whose distribution conditions are different, write to the author to ask for 237permission. For software which is copyrighted by the Free Software Foundation, 238write to the Free Software Foundation; we sometimes make exceptions for this. 239Our decision will be guided by the two goals of preserving the free status 240of all derivatives of our free software and of promoting the sharing and reuse 241of software generally. 242 243 NO WARRANTY 244 24511. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR 246THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE 247STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM 248"AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, 249BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 250FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE 251OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME 252THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. 253 25412. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 255WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE 256THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY 257GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE 258OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA 259OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES 260OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH 261HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. 262END OF TERMS AND CONDITIONS 263 264How to Apply These Terms to Your New Programs 265 266If you develop a new program, and you want it to be of the greatest possible 267use to the public, the best way to achieve this is to make it free software 268which everyone can redistribute and change under these terms. 269 270To do so, attach the following notices to the program. It is safest to attach 271them to the start of each source file to most effectively convey the exclusion 272of warranty; and each file should have at least the "copyright" line and a 273pointer to where the full notice is found. 274 275<one line to give the program's name and an idea of what it does.> 276 277Copyright (C)< yyyy> <name of author> 278 279This program is free software; you can redistribute it and/or modify it under 280the terms of the GNU General Public License as published by the Free Software 281Foundation; either version 2 of the License, or (at your option) any later 282version. 283 284This program is distributed in the hope that it will be useful, but WITHOUT 285ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 286FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. 287 288You should have received a copy of the GNU General Public License along with 289this program; if not, write to the Free Software Foundation, Inc., 51 Franklin 290Street, Fifth Floor, Boston, MA 02110-1301, USA. 291 292Also add information on how to contact you by electronic and paper mail. 293 294If the program is interactive, make it output a short notice like this when 295it starts in an interactive mode: 296 297Gnomovision version 69, Copyright (C) year name of author Gnomovision comes 298with ABSOLUTELY NO WARRANTY; for details type `show w'. This is free software, 299and you are welcome to redistribute it under certain conditions; type `show 300c' for details. 301 302The hypothetical commands `show w' and `show c' should show the appropriate 303parts of the General Public License. Of course, the commands you use may be 304called something other than `show w' and `show c'; they could even be mouse-clicks 305or menu items--whatever suits your program. 306 307You should also get your employer (if you work as a programmer) or your school, 308if any, to sign a "copyright disclaimer" for the program, if necessary. Here 309is a sample; alter the names: 310 311Yoyodyne, Inc., hereby disclaims all copyright interest in the program `Gnomovision' 312(which makes passes at compilers) written by James Hacker. 313 314<signature of Ty Coon >, 1 April 1989 Ty Coon, President of Vice This General 315Public License does not permit incorporating your program into proprietary 316programs. If your program is a subroutine library, you may consider it more 317useful to permit linking proprietary applications with the library. If this 318is what you want to do, use the GNU Lesser General Public License instead 319of this License. 320