1 GNU GENERAL PUBLIC LICENSE 2 Version 2, June 1991 3 4 Copyright (C) 1989, 1991 Free Software Foundation, Inc. 5 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA. 6 7 Everyone is permitted to copy and distribute verbatim copies 8 of this license document, but changing it is not allowed. 9 10 Preamble 11 12 The licenses for most software are designed to take away your 13freedom to share and change it. By contrast, the GNU General Public 14License is intended to guarantee your freedom to share and change free 15software--to make sure the software is free for all its users. This 16General Public License applies to most of the Free Software 17Foundation's software and to any other program whose authors commit to 18using it. (Some other Free Software Foundation software is covered by 19the GNU Library General Public License instead.) You can apply it to 20your programs, too. 21 22 When we speak of free software, we are referring to freedom, not 23price. Our General Public Licenses are designed to make sure that you 24have the freedom to distribute copies of free software (and charge for 25this service if you wish), that you receive source code or can get it 26if you want it, that you can change the software or use pieces of it 27in new free programs; and that you know you can do these things. 28 29 To protect your rights, we need to make restrictions that forbid 30anyone to deny you these rights or to ask you to surrender the rights. 31These restrictions translate to certain responsibilities for you if you 32distribute copies of the software, or if you modify it. 33 34 For example, if you distribute copies of such a program, whether 35gratis or for a fee, you must give the recipients all the rights that 36you have. You must make sure that they, too, receive or can get the 37source code. And you must show them these terms so they know their 38rights. 39 40 We protect your rights with two steps: (1) copyright the software, and 41(2) offer you this license which gives you legal permission to copy, 42distribute and/or modify the software. 43 44 Also, for each author's protection and ours, we want to make certain 45that everyone understands that there is no warranty for this free 46software. If the software is modified by someone else and passed on, we 47want its recipients to know that what they have is not the original, so 48that any problems introduced by others will not reflect on the original 49authors' reputations. 50 51 Finally, any free program is threatened constantly by software 52patents. We wish to avoid the danger that redistributors of a free 53program will individually obtain patent licenses, in effect making the 54program proprietary. To prevent this, we have made it clear that any 55patent must be licensed for everyone's free use or not licensed at all. 56 57 The precise terms and conditions for copying, distribution and 58modification follow. 59 60 GNU GENERAL PUBLIC LICENSE 61 TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 62 63 0. This License applies to any program or other work which contains 64a notice placed by the copyright holder saying it may be distributed 65under the terms of this General Public License. The "Program", below, 66refers to any such program or work, and a "work based on the Program" 67means either the Program or any derivative work under copyright law: 68that is to say, a work containing the Program or a portion of it, 69either verbatim or with modifications and/or translated into another 70language. (Hereinafter, translation is included without limitation in 71the term "modification".) Each licensee is addressed as "you". 72 73Activities other than copying, distribution and modification are not 74covered by this License; they are outside its scope. The act of 75running the Program is not restricted, and the output from the Program 76is covered only if its contents constitute a work based on the 77Program (independent of having been made by running the Program). 78Whether that is true depends on what the Program does. 79 80 1. You may copy and distribute verbatim copies of the Program's 81source code as you receive it, in any medium, provided that you 82conspicuously and appropriately publish on each copy an appropriate 83copyright notice and disclaimer of warranty; keep intact all the 84notices that refer to this License and to the absence of any warranty; 85and give any other recipients of the Program a copy of this License 86along with the Program. 87 88You may charge a fee for the physical act of transferring a copy, and 89you may at your option offer warranty protection in exchange for a fee. 90 91 2. You may modify your copy or copies of the Program or any portion 92of it, thus forming a work based on the Program, and copy and 93distribute such modifications or work under the terms of Section 1 94above, provided that you also meet all of these conditions: 95 96 a) You must cause the modified files to carry prominent notices 97 stating that you changed the files and the date of any change. 98 99 b) You must cause any work that you distribute or publish, that in 100 whole or in part contains or is derived from the Program or any 101 part thereof, to be licensed as a whole at no charge to all third 102 parties under the terms of this License. 103 104 c) If the modified program normally reads commands interactively 105 when run, you must cause it, when started running for such 106 interactive use in the most ordinary way, to print or display an 107 announcement including an appropriate copyright notice and a 108 notice that there is no warranty (or else, saying that you provide 109 a warranty) and that users may redistribute the program under 110 these conditions, and telling the user how to view a copy of this 111 License. (Exception: if the Program itself is interactive but 112 does not normally print such an announcement, your work based on 113 the Program is not required to print an announcement.) 114 115These requirements apply to the modified work as a whole. If 116identifiable sections of that work are not derived from the Program, 117and can be reasonably considered independent and separate works in 118themselves, then this License, and its terms, do not apply to those 119sections when you distribute them as separate works. But when you 120distribute the same sections as part of a whole which is a work based 121on the Program, the distribution of the whole must be on the terms of 122this License, whose permissions for other licensees extend to the 123entire whole, and thus to each and every part regardless of who wrote it. 124 125Thus, it is not the intent of this section to claim rights or contest 126your rights to work written entirely by you; rather, the intent is to 127exercise the right to control the distribution of derivative or 128collective works based on the Program. 129 130In addition, mere aggregation of another work not based on the Program 131with the Program (or with a work based on the Program) on a volume of 132a storage or distribution medium does not bring the other work under 133the scope of this License. 134 135 3. You may copy and distribute the Program (or a work based on it, 136under Section 2) in object code or executable form under the terms of 137Sections 1 and 2 above provided that you also do one of the following: 138 139 a) Accompany it with the complete corresponding machine-readable 140 source code, which must be distributed under the terms of Sections 141 1 and 2 above on a medium customarily used for software interchange; or, 142 143 b) Accompany it with a written offer, valid for at least three 144 years, to give any third party, for a charge no more than your 145 cost of physically performing source distribution, a complete 146 machine-readable copy of the corresponding source code, to be 147 distributed under the terms of Sections 1 and 2 above on a medium 148 customarily used for software interchange; or, 149 150 c) Accompany it with the information you received as to the offer 151 to distribute corresponding source code. (This alternative is 152 allowed only for noncommercial distribution and only if you 153 received the program in object code or executable form with such 154 an offer, in accord with Subsection b above.) 155 156The source code for a work means the preferred form of the work for 157making modifications to it. For an executable work, complete source 158code means all the source code for all modules it contains, plus any 159associated interface definition files, plus the scripts used to 160control compilation and installation of the executable. However, as a 161special exception, the source code distributed need not include 162anything that is normally distributed (in either source or binary 163form) with the major components (compiler, kernel, and so on) of the 164operating system on which the executable runs, unless that component 165itself accompanies the executable. 166 167If distribution of executable or object code is made by offering 168access to copy from a designated place, then offering equivalent 169access to copy the source code from the same place counts as 170distribution of the source code, even though third parties are not 171compelled to copy the source along with the object code. 172 173 4. You may not copy, modify, sublicense, or distribute the Program 174except as expressly provided under this License. Any attempt 175otherwise to copy, modify, sublicense or distribute the Program is 176void, and will automatically terminate your rights under this License. 177However, parties who have received copies, or rights, from you under 178this License will not have their licenses terminated so long as such 179parties remain in full compliance. 180 181 5. You are not required to accept this License, since you have not 182signed it. However, nothing else grants you permission to modify or 183distribute the Program or its derivative works. These actions are 184prohibited by law if you do not accept this License. Therefore, by 185modifying or distributing the Program (or any work based on the 186Program), you indicate your acceptance of this License to do so, and 187all its terms and conditions for copying, distributing or modifying 188the Program or works based on it. 189 190 6. Each time you redistribute the Program (or any work based on the 191Program), the recipient automatically receives a license from the 192original licensor to copy, distribute or modify the Program subject to 193these terms and conditions. You may not impose any further 194restrictions on the recipients' exercise of the rights granted herein. 195You are not responsible for enforcing compliance by third parties to 196this License. 197 198 7. If, as a consequence of a court judgment or allegation of patent 199infringement or for any other reason (not limited to patent issues), 200conditions are imposed on you (whether by court order, agreement or 201otherwise) that contradict the conditions of this License, they do not 202excuse you from the conditions of this License. If you cannot 203distribute so as to satisfy simultaneously your obligations under this 204License and any other pertinent obligations, then as a consequence you 205may not distribute the Program at all. For example, if a patent 206license would not permit royalty-free redistribution of the Program by 207all those who receive copies directly or indirectly through you, then 208the only way you could satisfy both it and this License would be to 209refrain entirely from distribution of the Program. 210 211If any portion of this section is held invalid or unenforceable under 212any particular circumstance, the balance of the section is intended to 213apply and the section as a whole is intended to apply in other 214circumstances. 215 216It is not the purpose of this section to induce you to infringe any 217patents or other property right claims or to contest validity of any 218such claims; this section has the sole purpose of protecting the 219integrity of the free software distribution system, which is 220implemented by public license practices. Many people have made 221generous contributions to the wide range of software distributed 222through that system in reliance on consistent application of that 223system; it is up to the author/donor to decide if he or she is willing 224to distribute software through any other system and a licensee cannot 225impose that choice. 226 227This section is intended to make thoroughly clear what is believed to 228be a consequence of the rest of this License. 229 230 8. If the distribution and/or use of the Program is restricted in 231certain countries either by patents or by copyrighted interfaces, the 232original copyright holder who places the Program under this License 233may add an explicit geographical distribution limitation excluding 234those countries, so that distribution is permitted only in or among 235countries not thus excluded. In such case, this License incorporates 236the limitation as if written in the body of this License. 237 238 9. The Free Software Foundation may publish revised and/or new versions 239of the General Public License from time to time. Such new versions will 240be similar in spirit to the present version, but may differ in detail to 241address new problems or concerns. 242 243Each version is given a distinguishing version number. If the Program 244specifies a version number of this License which applies to it and "any 245later version", you have the option of following the terms and conditions 246either of that version or of any later version published by the Free 247Software Foundation. If the Program does not specify a version number of 248this License, you may choose any version ever published by the Free Software 249Foundation. 250 251 10. If you wish to incorporate parts of the Program into other free 252programs whose distribution conditions are different, write to the author 253to ask for permission. For software which is copyrighted by the Free 254Software Foundation, write to the Free Software Foundation; we sometimes 255make exceptions for this. Our decision will be guided by the two goals 256of preserving the free status of all derivatives of our free software and 257of promoting the sharing and reuse of software generally. 258 259 NO WARRANTY 260 261 11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY 262FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN 263OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES 264PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED 265OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 266MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS 267TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE 268PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, 269REPAIR OR CORRECTION. 270 271 12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 272WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR 273REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, 274INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING 275OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED 276TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY 277YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER 278PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE 279POSSIBILITY OF SUCH DAMAGES. 280 281 END OF TERMS AND CONDITIONS 282 283 Appendix: How to Apply These Terms to Your New Programs 284 285 If you develop a new program, and you want it to be of the greatest 286possible use to the public, the best way to achieve this is to make it 287free software which everyone can redistribute and change under these terms. 288 289 To do so, attach the following notices to the program. It is safest 290to attach them to the start of each source file to most effectively 291convey the exclusion of warranty; and each file should have at least 292the "copyright" line and a pointer to where the full notice is found. 293 294 <one line to give the program's name and a brief idea of what it does.> 295 Copyright (C) 19yy <name of author> 296 297 This program is free software; you can redistribute it and/or modify 298 it under the terms of the GNU General Public License as published by 299 the Free Software Foundation; either version 2 of the License, or 300 (at your option) any later version. 301 302 This program is distributed in the hope that it will be useful, 303 but WITHOUT ANY WARRANTY; without even the implied warranty of 304 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 305 GNU General Public License for more details. 306 307 You should have received a copy of the GNU General Public License 308 along with this program; if not, write to the Free Software 309 Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA. 310 311Also add information on how to contact you by electronic and paper mail. 312 313If the program is interactive, make it output a short notice like this 314when it starts in an interactive mode: 315 316 Gnomovision version 69, Copyright (C) 19yy name of author 317 Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 318 This is free software, and you are welcome to redistribute it 319 under certain conditions; type `show c' for details. 320 321The hypothetical commands `show w' and `show c' should show the appropriate 322parts of the General Public License. Of course, the commands you use may 323be called something other than `show w' and `show c'; they could even be 324mouse-clicks or menu items--whatever suits your program. 325 326You should also get your employer (if you work as a programmer) or your 327school, if any, to sign a "copyright disclaimer" for the program, if 328necessary. Here is a sample; alter the names: 329 330 Yoyodyne, Inc., hereby disclaims all copyright interest in the program 331 `Gnomovision' (which makes passes at compilers) written by James Hacker. 332 333 <signature of Ty Coon>, 1 April 1989 334 Ty Coon, President of Vice 335 336This General Public License does not permit incorporating your program into 337proprietary programs. If your program is a subroutine library, you may 338consider it more useful to permit linking proprietary applications with the 339library. If this is what you want to do, use the GNU Library General 340Public License instead of this License. 341