1 GNU GENERAL PUBLIC LICENSE 2 Version 2, June 1991 3 4 Copyright (C) 1989, 1991 Free Software Foundation, Inc., 5 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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 12freedom to share and change it. By contrast, the GNU General Public 13License is intended to guarantee your freedom to share and change free 14software--to make sure the software is free for all its users. This 15General Public License applies to most of the Free Software 16Foundation's software and to any other program whose authors commit to 17using it. (Some other Free Software Foundation software is covered by 18the GNU Lesser General Public License instead.) You can apply it to 19your programs, too. 20 21 When we speak of free software, we are referring to freedom, not 22price. Our General Public Licenses are designed to make sure that you 23have the freedom to distribute copies of free software (and charge for 24this service if you wish), that you receive source code or can get it 25if you want it, that you can change the software or use pieces of it 26in 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 29anyone to deny you these rights or to ask you to surrender the rights. 30These restrictions translate to certain responsibilities for you if you 31distribute copies of the software, or if you modify it. 32 33 For example, if you distribute copies of such a program, whether 34gratis or for a fee, you must give the recipients all the rights that 35you have. You must make sure that they, too, receive or can get the 36source code. And you must show them these terms so they know their 37rights. 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, 41distribute and/or modify the software. 42 43 Also, for each author's protection and ours, we want to make certain 44that everyone understands that there is no warranty for this free 45software. If the software is modified by someone else and passed on, we 46want its recipients to know that what they have is not the original, so 47that any problems introduced by others will not reflect on the original 48authors' reputations. 49 50 Finally, any free program is threatened constantly by software 51patents. We wish to avoid the danger that redistributors of a free 52program will individually obtain patent licenses, in effect making the 53program proprietary. To prevent this, we have made it clear that any 54patent must be licensed for everyone's free use or not licensed at all. 55 56 The precise terms and conditions for copying, distribution and 57modification follow. 58 59 GNU GENERAL PUBLIC LICENSE 60 TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 61 62 0. This License applies to any program or other work which contains 63a notice placed by the copyright holder saying it may be distributed 64under the terms of this General Public License. The "Program", below, 65refers to any such program or work, and a "work based on the Program" 66means either the Program or any derivative work under copyright law: 67that is to say, a work containing the Program or a portion of it, 68either verbatim or with modifications and/or translated into another 69language. (Hereinafter, translation is included without limitation in 70the term "modification".) Each licensee is addressed as "you". 71 72Activities other than copying, distribution and modification are not 73covered by this License; they are outside its scope. The act of 74running the Program is not restricted, and the output from the Program 75is covered only if its contents constitute a work based on the 76Program (independent of having been made by running the Program). 77Whether that is true depends on what the Program does. 78 79 1. You may copy and distribute verbatim copies of the Program's 80source code as you receive it, in any medium, provided that you 81conspicuously and appropriately publish on each copy an appropriate 82copyright notice and disclaimer of warranty; keep intact all the 83notices that refer to this License and to the absence of any warranty; 84and give any other recipients of the Program a copy of this License 85along with the Program. 86 87You may charge a fee for the physical act of transferring a copy, and 88you may at your option offer warranty protection in exchange for a fee. 89 90 2. You may modify your copy or copies of the Program or any portion 91of it, thus forming a work based on the Program, and copy and 92distribute such modifications or work under the terms of Section 1 93above, provided that you also meet all of these conditions: 94 95 a) You must cause the modified files to carry prominent notices 96 stating that you changed the files and the date of any change. 97 98 b) You must cause any work that you distribute or publish, that in 99 whole or in part contains or is derived from the Program or any 100 part thereof, to be licensed as a whole at no charge to all third 101 parties under the terms of this License. 102 103 c) If the modified program normally reads commands interactively 104 when run, you must cause it, when started running for such 105 interactive use in the most ordinary way, to print or display an 106 announcement including an appropriate copyright notice and a 107 notice that there is no warranty (or else, saying that you provide 108 a warranty) and that users may redistribute the program under 109 these conditions, and telling the user how to view a copy of this 110 License. (Exception: if the Program itself is interactive but 111 does not normally print such an announcement, your work based on 112 the Program is not required to print an announcement.) 113 114These requirements apply to the modified work as a whole. If 115identifiable sections of that work are not derived from the Program, 116and can be reasonably considered independent and separate works in 117themselves, then this License, and its terms, do not apply to those 118sections when you distribute them as separate works. But when you 119distribute the same sections as part of a whole which is a work based 120on the Program, the distribution of the whole must be on the terms of 121this License, whose permissions for other licensees extend to the 122entire whole, and thus to each and every part regardless of who wrote it. 123 124Thus, it is not the intent of this section to claim rights or contest 125your rights to work written entirely by you; rather, the intent is to 126exercise the right to control the distribution of derivative or 127collective works based on the Program. 128 129In addition, mere aggregation of another work not based on the Program 130with the Program (or with a work based on the Program) on a volume of 131a storage or distribution medium does not bring the other work under 132the scope of this License. 133 134 3. You may copy and distribute the Program (or a work based on it, 135under Section 2) in object code or executable form under the terms of 136Sections 1 and 2 above provided that you also do one of the following: 137 138 a) Accompany it with the complete corresponding machine-readable 139 source code, which must be distributed under the terms of Sections 140 1 and 2 above on a medium customarily used for software interchange; or, 141 142 b) Accompany it with a written offer, valid for at least three 143 years, to give any third party, for a charge no more than your 144 cost of physically performing source distribution, a complete 145 machine-readable copy of the corresponding source code, to be 146 distributed under the terms of Sections 1 and 2 above on a medium 147 customarily used for software interchange; or, 148 149 c) Accompany it with the information you received as to the offer 150 to distribute corresponding source code. (This alternative is 151 allowed only for noncommercial distribution and only if you 152 received the program in object code or executable form with such 153 an offer, in accord with Subsection b above.) 154 155The source code for a work means the preferred form of the work for 156making modifications to it. For an executable work, complete source 157code means all the source code for all modules it contains, plus any 158associated interface definition files, plus the scripts used to 159control compilation and installation of the executable. However, as a 160special exception, the source code distributed need not include 161anything that is normally distributed (in either source or binary 162form) with the major components (compiler, kernel, and so on) of the 163operating system on which the executable runs, unless that component 164itself accompanies the executable. 165 166If distribution of executable or object code is made by offering 167access to copy from a designated place, then offering equivalent 168access to copy the source code from the same place counts as 169distribution of the source code, even though third parties are not 170compelled to copy the source along with the object code. 171 172 4. You may not copy, modify, sublicense, or distribute the Program 173except as expressly provided under this License. Any attempt 174otherwise to copy, modify, sublicense or distribute the Program is 175void, and will automatically terminate your rights under this License. 176However, parties who have received copies, or rights, from you under 177this License will not have their licenses terminated so long as such 178parties remain in full compliance. 179 180 5. You are not required to accept this License, since you have not 181signed it. However, nothing else grants you permission to modify or 182distribute the Program or its derivative works. These actions are 183prohibited by law if you do not accept this License. Therefore, by 184modifying or distributing the Program (or any work based on the 185Program), you indicate your acceptance of this License to do so, and 186all its terms and conditions for copying, distributing or modifying 187the Program or works based on it. 188 189 6. Each time you redistribute the Program (or any work based on the 190Program), the recipient automatically receives a license from the 191original licensor to copy, distribute or modify the Program subject to 192these terms and conditions. You may not impose any further 193restrictions on the recipients' exercise of the rights granted herein. 194You are not responsible for enforcing compliance by third parties to 195this License. 196 197 7. If, as a consequence of a court judgment or allegation of patent 198infringement or for any other reason (not limited to patent issues), 199conditions are imposed on you (whether by court order, agreement or 200otherwise) that contradict the conditions of this License, they do not 201excuse you from the conditions of this License. If you cannot 202distribute so as to satisfy simultaneously your obligations under this 203License and any other pertinent obligations, then as a consequence you 204may not distribute the Program at all. For example, if a patent 205license would not permit royalty-free redistribution of the Program by 206all those who receive copies directly or indirectly through you, then 207the only way you could satisfy both it and this License would be to 208refrain entirely from distribution of the Program. 209 210If any portion of this section is held invalid or unenforceable under 211any particular circumstance, the balance of the section is intended to 212apply and the section as a whole is intended to apply in other 213circumstances. 214 215It is not the purpose of this section to induce you to infringe any 216patents or other property right claims or to contest validity of any 217such claims; this section has the sole purpose of protecting the 218integrity of the free software distribution system, which is 219implemented by public license practices. Many people have made 220generous contributions to the wide range of software distributed 221through that system in reliance on consistent application of that 222system; it is up to the author/donor to decide if he or she is willing 223to distribute software through any other system and a licensee cannot 224impose that choice. 225 226This section is intended to make thoroughly clear what is believed to 227be a consequence of the rest of this License. 228 229 8. If the distribution and/or use of the Program is restricted in 230certain countries either by patents or by copyrighted interfaces, the 231original copyright holder who places the Program under this License 232may add an explicit geographical distribution limitation excluding 233those countries, so that distribution is permitted only in or among 234countries not thus excluded. In such case, this License incorporates 235the limitation as if written in the body of this License. 236 237 9. The Free Software Foundation may publish revised and/or new versions 238of the General Public License from time to time. Such new versions will 239be similar in spirit to the present version, but may differ in detail to 240address new problems or concerns. 241 242Each version is given a distinguishing version number. If the Program 243specifies a version number of this License which applies to it and "any 244later version", you have the option of following the terms and conditions 245either of that version or of any later version published by the Free 246Software Foundation. If the Program does not specify a version number of 247this License, you may choose any version ever published by the Free Software 248Foundation. 249 250 10. If you wish to incorporate parts of the Program into other free 251programs whose distribution conditions are different, write to the author 252to ask for permission. For software which is copyrighted by the Free 253Software Foundation, write to the Free Software Foundation; we sometimes 254make exceptions for this. Our decision will be guided by the two goals 255of preserving the free status of all derivatives of our free software and 256of promoting the sharing and reuse of software generally. 257 258 NO WARRANTY 259 260 11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY 261FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN 262OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES 263PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED 264OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 265MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS 266TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE 267PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, 268REPAIR OR CORRECTION. 269 270 12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 271WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR 272REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, 273INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING 274OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED 275TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY 276YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER 277PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE 278POSSIBILITY OF SUCH DAMAGES. 279 280 END OF TERMS AND CONDITIONS 281 282 How to Apply These Terms to Your New Programs 283 284 If you develop a new program, and you want it to be of the greatest 285possible use to the public, the best way to achieve this is to make it 286free software which everyone can redistribute and change under these terms. 287 288 To do so, attach the following notices to the program. It is safest 289to attach them to the start of each source file to most effectively 290convey the exclusion of warranty; and each file should have at least 291the "copyright" line and a pointer to where the full notice is found. 292 293 <one line to give the program's name and a brief idea of what it does.> 294 Copyright (C) <year> <name of author> 295 296 This program is free software; you can redistribute it and/or modify 297 it under the terms of the GNU General Public License as published by 298 the Free Software Foundation; either version 2 of the License, or 299 (at your option) any later version. 300 301 This program is distributed in the hope that it will be useful, 302 but WITHOUT ANY WARRANTY; without even the implied warranty of 303 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 304 GNU General Public License for more details. 305 306 You should have received a copy of the GNU General Public License along 307 with this program; if not, write to the Free Software Foundation, Inc., 308 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 309 310Also add information on how to contact you by electronic and paper mail. 311 312If the program is interactive, make it output a short notice like this 313when it starts in an interactive mode: 314 315 Gnomovision version 69, Copyright (C) year name of author 316 Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 317 This is free software, and you are welcome to redistribute it 318 under certain conditions; type `show c' for details. 319 320The hypothetical commands `show w' and `show c' should show the appropriate 321parts of the General Public License. Of course, the commands you use may 322be called something other than `show w' and `show c'; they could even be 323mouse-clicks or menu items--whatever suits your program. 324 325You should also get your employer (if you work as a programmer) or your 326school, if any, to sign a "copyright disclaimer" for the program, if 327necessary. Here is a sample; alter the names: 328 329 Yoyodyne, Inc., hereby disclaims all copyright interest in the program 330 `Gnomovision' (which makes passes at compilers) written by James Hacker. 331 332 <signature of Ty Coon>, 1 April 1989 333 Ty Coon, President of Vice 334 335This General Public License does not permit incorporating your program into 336proprietary programs. If your program is a subroutine library, you may 337consider it more useful to permit linking proprietary applications with the 338library. If this is what you want to do, use the GNU Lesser General 339Public License instead of this License.