1 GNU GENERAL PUBLIC LICENSE 2 Version 2, June 1991 3 4 Copyright (C) 1989, 1991 Free Software Foundation, Inc. 5 675 Mass Ave, Cambridge, MA 02139, USA 6 Everyone is permitted to copy and distribute verbatim copies 7 of this license document, but changing it is not allowed. 8 9 Preamble 10 11 The licenses for most software are designed to take away your 12 freedom to share and change it. By contrast, the GNU General Public 13 License is intended to guarantee your freedom to share and change free 14 software--to make sure the software is free for all its users. This 15 General Public License applies to most of the Free Software 16 Foundation's software and to any other program whose authors commit to 17 using it. (Some other Free Software Foundation software is covered by 18 the GNU Library General Public License instead.) You can apply it to 19 your programs, too. 20 21 When we speak of free software, we are referring to freedom, not 22 price. Our General Public Licenses are designed to make sure that you 23 have the freedom to distribute copies of free software (and charge for 24 this service if you wish), that you receive source code or can get it 25 if you want it, that you can change the software or use pieces of it 26 in new free programs; and that you know you can do these things. 27 28 To protect your rights, we need to make restrictions that forbid 29 anyone to deny you these rights or to ask you to surrender the rights. 30 These restrictions translate to certain responsibilities for you if you 31 distribute copies of the software, or if you modify it. 32 33 For example, if you distribute copies of such a program, whether 34 gratis or for a fee, you must give the recipients all the rights that 35 you have. You must make sure that they, too, receive or can get the 36 source code. And you must show them these terms so they know their 37 rights. 38 39 We protect your rights with two steps: (1) copyright the software, and 40 (2) offer you this license which gives you legal permission to copy, 41 distribute and/or modify the software. 42 43 Also, for each author's protection and ours, we want to make certain 44 that everyone understands that there is no warranty for this free 45 software. If the software is modified by someone else and passed on, we 46 want its recipients to know that what they have is not the original, so 47 that any problems introduced by others will not reflect on the original 48 authors' reputations. 49 50 Finally, any free program is threatened constantly by software 51 patents. We wish to avoid the danger that redistributors of a free 52 program will individually obtain patent licenses, in effect making the 53 program proprietary. To prevent this, we have made it clear that any 54 patent must be licensed for everyone's free use or not licensed at all. 55 56 The precise terms and conditions for copying, distribution and 57 modification follow. 58 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 64 a notice placed by the copyright holder saying it may be distributed 65 under the terms of this General Public License. The "Program", below, 66 refers to any such program or work, and a "work based on the Program" 67 means either the Program or any derivative work under copyright law: 68 that is to say, a work containing the Program or a portion of it, 69 either verbatim or with modifications and/or translated into another 70 language. (Hereinafter, translation is included without limitation in 71 the term "modification".) Each licensee is addressed as "you". 72 73 Activities other than copying, distribution and modification are not 74 covered by this License; they are outside its scope. The act of 75 running the Program is not restricted, and the output from the Program 76 is covered only if its contents constitute a work based on the 77 Program (independent of having been made by running the Program). 78 Whether that is true depends on what the Program does. 79 80 1. You may copy and distribute verbatim copies of the Program's 81 source code as you receive it, in any medium, provided that you 82 conspicuously and appropriately publish on each copy an appropriate 83 copyright notice and disclaimer of warranty; keep intact all the 84 notices that refer to this License and to the absence of any warranty; 85 and give any other recipients of the Program a copy of this License 86 along with the Program. 87 88 You may charge a fee for the physical act of transferring a copy, and 89 you 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 92 of it, thus forming a work based on the Program, and copy and 93 distribute such modifications or work under the terms of Section 1 94 above, 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.) 114 116 These requirements apply to the modified work as a whole. If 117 identifiable sections of that work are not derived from the Program, 118 and can be reasonably considered independent and separate works in 119 themselves, then this License, and its terms, do not apply to those 120 sections when you distribute them as separate works. But when you 121 distribute the same sections as part of a whole which is a work based 122 on the Program, the distribution of the whole must be on the terms of 123 this License, whose permissions for other licensees extend to the 124 entire whole, and thus to each and every part regardless of who wrote it. 125 126 Thus, it is not the intent of this section to claim rights or contest 127 your rights to work written entirely by you; rather, the intent is to 128 exercise the right to control the distribution of derivative or 129 collective works based on the Program. 130 131 In addition, mere aggregation of another work not based on the Program 132 with the Program (or with a work based on the Program) on a volume of 133 a storage or distribution medium does not bring the other work under 134 the scope of this License. 135 136 3. You may copy and distribute the Program (or a work based on it, 137 under Section 2) in object code or executable form under the terms of 138 Sections 1 and 2 above provided that you also do one of the following: 139 140 a) Accompany it with the complete corresponding machine-readable 141 source code, which must be distributed under the terms of Sections 142 1 and 2 above on a medium customarily used for software interchange; or, 143 144 b) Accompany it with a written offer, valid for at least three 145 years, to give any third party, for a charge no more than your 146 cost of physically performing source distribution, a complete 147 machine-readable copy of the corresponding source code, to be 148 distributed under the terms of Sections 1 and 2 above on a medium 149 customarily used for software interchange; or, 150 151 c) Accompany it with the information you received as to the offer 152 to distribute corresponding source code. (This alternative is 153 allowed only for noncommercial distribution and only if you 154 received the program in object code or executable form with such 155 an offer, in accord with Subsection b above.) 156 157 The source code for a work means the preferred form of the work for 158 making modifications to it. For an executable work, complete source 159 code means all the source code for all modules it contains, plus any 160 associated interface definition files, plus the scripts used to 161 control compilation and installation of the executable. However, as a 162 special exception, the source code distributed need not include 163 anything that is normally distributed (in either source or binary 164 form) with the major components (compiler, kernel, and so on) of the 165 operating system on which the executable runs, unless that component 166 itself accompanies the executable. 167 168 If distribution of executable or object code is made by offering 169 access to copy from a designated place, then offering equivalent 170 access to copy the source code from the same place counts as 171 distribution of the source code, even though third parties are not 172 compelled to copy the source along with the object code. 173 175 4. You may not copy, modify, sublicense, or distribute the Program 176 except as expressly provided under this License. Any attempt 177 otherwise to copy, modify, sublicense or distribute the Program is 178 void, and will automatically terminate your rights under this License. 179 However, parties who have received copies, or rights, from you under 180 this License will not have their licenses terminated so long as such 181 parties remain in full compliance. 182 183 5. You are not required to accept this License, since you have not 184 signed it. However, nothing else grants you permission to modify or 185 distribute the Program or its derivative works. These actions are 186 prohibited by law if you do not accept this License. Therefore, by 187 modifying or distributing the Program (or any work based on the 188 Program), you indicate your acceptance of this License to do so, and 189 all its terms and conditions for copying, distributing or modifying 190 the Program or works based on it. 191 192 6. Each time you redistribute the Program (or any work based on the 193 Program), the recipient automatically receives a license from the 194 original licensor to copy, distribute or modify the Program subject to 195 these terms and conditions. You may not impose any further 196 restrictions on the recipients' exercise of the rights granted herein. 197 You are not responsible for enforcing compliance by third parties to 198 this License. 199 200 7. If, as a consequence of a court judgment or allegation of patent 201 infringement or for any other reason (not limited to patent issues), 202 conditions are imposed on you (whether by court order, agreement or 203 otherwise) that contradict the conditions of this License, they do not 204 excuse you from the conditions of this License. If you cannot 205 distribute so as to satisfy simultaneously your obligations under this 206 License and any other pertinent obligations, then as a consequence you 207 may not distribute the Program at all. For example, if a patent 208 license would not permit royalty-free redistribution of the Program by 209 all those who receive copies directly or indirectly through you, then 210 the only way you could satisfy both it and this License would be to 211 refrain entirely from distribution of the Program. 212 213 If any portion of this section is held invalid or unenforceable under 214 any particular circumstance, the balance of the section is intended to 215 apply and the section as a whole is intended to apply in other 216 circumstances. 217 218 It is not the purpose of this section to induce you to infringe any 219 patents or other property right claims or to contest validity of any 220 such claims; this section has the sole purpose of protecting the 221 integrity of the free software distribution system, which is 222 implemented by public license practices. Many people have made 223 generous contributions to the wide range of software distributed 224 through that system in reliance on consistent application of that 225 system; it is up to the author/donor to decide if he or she is willing 226 to distribute software through any other system and a licensee cannot 227 impose that choice. 228 229 This section is intended to make thoroughly clear what is believed to 230 be a consequence of the rest of this License. 231 233 8. If the distribution and/or use of the Program is restricted in 234 certain countries either by patents or by copyrighted interfaces, the 235 original copyright holder who places the Program under this License 236 may add an explicit geographical distribution limitation excluding 237 those countries, so that distribution is permitted only in or among 238 countries not thus excluded. In such case, this License incorporates 239 the limitation as if written in the body of this License. 240 241 9. The Free Software Foundation may publish revised and/or new versions 242 of the General Public License from time to time. Such new versions will 243 be similar in spirit to the present version, but may differ in detail to 244 address new problems or concerns. 245 246 Each version is given a distinguishing version number. If the Program 247 specifies a version number of this License which applies to it and "any 248 later version", you have the option of following the terms and conditions 249 either of that version or of any later version published by the Free 250 Software Foundation. If the Program does not specify a version number of 251 this License, you may choose any version ever published by the Free Software 252 Foundation. 253 254 10. If you wish to incorporate parts of the Program into other free 255 programs whose distribution conditions are different, write to the author 256 to ask for permission. For software which is copyrighted by the Free 257 Software Foundation, write to the Free Software Foundation; we sometimes 258 make exceptions for this. Our decision will be guided by the two goals 259 of preserving the free status of all derivatives of our free software and 260 of promoting the sharing and reuse of software generally. 261 262 NO WARRANTY 263 264 11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY 265 FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN 266 OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES 267 PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED 268 OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 269 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS 270 TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE 271 PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, 272 REPAIR OR CORRECTION. 273 274 12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 275 WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR 276 REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, 277 INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING 278 OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED 279 TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY 280 YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER 281 PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE 282 POSSIBILITY OF SUCH DAMAGES. 283 284 END OF TERMS AND CONDITIONS 285 287 Appendix: How to Apply These Terms to Your New Programs 288 289 If you develop a new program, and you want it to be of the greatest 290 possible use to the public, the best way to achieve this is to make it 291 free software which everyone can redistribute and change under these terms. 292 293 To do so, attach the following notices to the program. It is safest 294 to attach them to the start of each source file to most effectively 295 convey the exclusion of warranty; and each file should have at least 296 the "copyright" line and a pointer to where the full notice is found. 297 298 <one line to give the program's name and a brief idea of what it does.> 299 Copyright (C) 19yy <name of author> 300 301 This program is free software; you can redistribute it and/or modify 302 it under the terms of the GNU General Public License as published by 303 the Free Software Foundation; either version 2 of the License, or 304 (at your option) any later version. 305 306 This program is distributed in the hope that it will be useful, 307 but WITHOUT ANY WARRANTY; without even the implied warranty of 308 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 309 GNU General Public License for more details. 310 311 You should have received a copy of the GNU General Public License 312 along with this program; if not, write to the Free Software 313 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 314 315 Also add information on how to contact you by electronic and paper mail. 316 317 If the program is interactive, make it output a short notice like this 318 when it starts in an interactive mode: 319 320 Gnomovision version 69, Copyright (C) 19yy name of author 321 Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 322 This is free software, and you are welcome to redistribute it 323 under certain conditions; type `show c' for details. 324 325 The hypothetical commands `show w' and `show c' should show the appropriate 326 parts of the General Public License. Of course, the commands you use may 327 be called something other than `show w' and `show c'; they could even be 328 mouse-clicks or menu items--whatever suits your program. 329 330 You should also get your employer (if you work as a programmer) or your 331 school, if any, to sign a "copyright disclaimer" for the program, if 332 necessary. Here is a sample; alter the names: 333 334 Yoyodyne, Inc., hereby disclaims all copyright interest in the program 335 `Gnomovision' (which makes passes at compilers) written by James Hacker. 336 337 <signature of Ty Coon>, 1 April 1989 338 Ty Coon, President of Vice 339 340 This General Public License does not permit incorporating your program into 341 proprietary programs. If your program is a subroutine library, you may 342 consider it more useful to permit linking proprietary applications with the 343 library. If this is what you want to do, use the GNU Library General 344 Public License instead of this License. 345