1Copyright (C) 1998-2019 Ivo Timmermans, Guus Sliepen and others. 2See the AUTHORS file for a complete list. 3 4This program is free software; you can redistribute it and/or modify it under 5the terms of the GNU General Public License as published by the Free Software 6Foundation; either version 2 of the License, or (at your option) any later 7version. 8 9 10 GNU GENERAL PUBLIC LICENSE 11 Version 2, June 1991 12 13 Copyright (C) 1989, 1991 Free Software Foundation, Inc., 14 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 15 Everyone is permitted to copy and distribute verbatim copies 16 of this license document, but changing it is not allowed. 17 18 Preamble 19 20 The licenses for most software are designed to take away your 21freedom to share and change it. By contrast, the GNU General Public 22License is intended to guarantee your freedom to share and change free 23software--to make sure the software is free for all its users. This 24General Public License applies to most of the Free Software 25Foundation's software and to any other program whose authors commit to 26using it. (Some other Free Software Foundation software is covered by 27the GNU Lesser General Public License instead.) You can apply it to 28your programs, too. 29 30 When we speak of free software, we are referring to freedom, not 31price. Our General Public Licenses are designed to make sure that you 32have the freedom to distribute copies of free software (and charge for 33this service if you wish), that you receive source code or can get it 34if you want it, that you can change the software or use pieces of it 35in new free programs; and that you know you can do these things. 36 37 To protect your rights, we need to make restrictions that forbid 38anyone to deny you these rights or to ask you to surrender the rights. 39These restrictions translate to certain responsibilities for you if you 40distribute copies of the software, or if you modify it. 41 42 For example, if you distribute copies of such a program, whether 43gratis or for a fee, you must give the recipients all the rights that 44you have. You must make sure that they, too, receive or can get the 45source code. And you must show them these terms so they know their 46rights. 47 48 We protect your rights with two steps: (1) copyright the software, and 49(2) offer you this license which gives you legal permission to copy, 50distribute and/or modify the software. 51 52 Also, for each author's protection and ours, we want to make certain 53that everyone understands that there is no warranty for this free 54software. If the software is modified by someone else and passed on, we 55want its recipients to know that what they have is not the original, so 56that any problems introduced by others will not reflect on the original 57authors' reputations. 58 59 Finally, any free program is threatened constantly by software 60patents. We wish to avoid the danger that redistributors of a free 61program will individually obtain patent licenses, in effect making the 62program proprietary. To prevent this, we have made it clear that any 63patent must be licensed for everyone's free use or not licensed at all. 64 65 The precise terms and conditions for copying, distribution and 66modification follow. 67 68 GNU GENERAL PUBLIC LICENSE 69 TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 70 71 0. This License applies to any program or other work which contains 72a notice placed by the copyright holder saying it may be distributed 73under the terms of this General Public License. The "Program", below, 74refers to any such program or work, and a "work based on the Program" 75means either the Program or any derivative work under copyright law: 76that is to say, a work containing the Program or a portion of it, 77either verbatim or with modifications and/or translated into another 78language. (Hereinafter, translation is included without limitation in 79the term "modification".) Each licensee is addressed as "you". 80 81Activities other than copying, distribution and modification are not 82covered by this License; they are outside its scope. The act of 83running the Program is not restricted, and the output from the Program 84is covered only if its contents constitute a work based on the 85Program (independent of having been made by running the Program). 86Whether that is true depends on what the Program does. 87 88 1. You may copy and distribute verbatim copies of the Program's 89source code as you receive it, in any medium, provided that you 90conspicuously and appropriately publish on each copy an appropriate 91copyright notice and disclaimer of warranty; keep intact all the 92notices that refer to this License and to the absence of any warranty; 93and give any other recipients of the Program a copy of this License 94along with the Program. 95 96You may charge a fee for the physical act of transferring a copy, and 97you may at your option offer warranty protection in exchange for a fee. 98 99 2. You may modify your copy or copies of the Program or any portion 100of it, thus forming a work based on the Program, and copy and 101distribute such modifications or work under the terms of Section 1 102above, provided that you also meet all of these conditions: 103 104 a) You must cause the modified files to carry prominent notices 105 stating that you changed the files and the date of any change. 106 107 b) You must cause any work that you distribute or publish, that in 108 whole or in part contains or is derived from the Program or any 109 part thereof, to be licensed as a whole at no charge to all third 110 parties under the terms of this License. 111 112 c) If the modified program normally reads commands interactively 113 when run, you must cause it, when started running for such 114 interactive use in the most ordinary way, to print or display an 115 announcement including an appropriate copyright notice and a 116 notice that there is no warranty (or else, saying that you provide 117 a warranty) and that users may redistribute the program under 118 these conditions, and telling the user how to view a copy of this 119 License. (Exception: if the Program itself is interactive but 120 does not normally print such an announcement, your work based on 121 the Program is not required to print an announcement.) 122 123These requirements apply to the modified work as a whole. If 124identifiable sections of that work are not derived from the Program, 125and can be reasonably considered independent and separate works in 126themselves, then this License, and its terms, do not apply to those 127sections when you distribute them as separate works. But when you 128distribute the same sections as part of a whole which is a work based 129on the Program, the distribution of the whole must be on the terms of 130this License, whose permissions for other licensees extend to the 131entire whole, and thus to each and every part regardless of who wrote it. 132 133Thus, it is not the intent of this section to claim rights or contest 134your rights to work written entirely by you; rather, the intent is to 135exercise the right to control the distribution of derivative or 136collective works based on the Program. 137 138In addition, mere aggregation of another work not based on the Program 139with the Program (or with a work based on the Program) on a volume of 140a storage or distribution medium does not bring the other work under 141the scope of this License. 142 143 3. You may copy and distribute the Program (or a work based on it, 144under Section 2) in object code or executable form under the terms of 145Sections 1 and 2 above provided that you also do one of the following: 146 147 a) Accompany it with the complete corresponding machine-readable 148 source code, which must be distributed under the terms of Sections 149 1 and 2 above on a medium customarily used for software interchange; or, 150 151 b) Accompany it with a written offer, valid for at least three 152 years, to give any third party, for a charge no more than your 153 cost of physically performing source distribution, a complete 154 machine-readable copy of the corresponding source code, to be 155 distributed under the terms of Sections 1 and 2 above on a medium 156 customarily used for software interchange; or, 157 158 c) Accompany it with the information you received as to the offer 159 to distribute corresponding source code. (This alternative is 160 allowed only for noncommercial distribution and only if you 161 received the program in object code or executable form with such 162 an offer, in accord with Subsection b above.) 163 164The source code for a work means the preferred form of the work for 165making modifications to it. For an executable work, complete source 166code means all the source code for all modules it contains, plus any 167associated interface definition files, plus the scripts used to 168control compilation and installation of the executable. However, as a 169special exception, the source code distributed need not include 170anything that is normally distributed (in either source or binary 171form) with the major components (compiler, kernel, and so on) of the 172operating system on which the executable runs, unless that component 173itself accompanies the executable. 174 175If distribution of executable or object code is made by offering 176access to copy from a designated place, then offering equivalent 177access to copy the source code from the same place counts as 178distribution of the source code, even though third parties are not 179compelled to copy the source along with the object code. 180 181 4. You may not copy, modify, sublicense, or distribute the Program 182except as expressly provided under this License. Any attempt 183otherwise to copy, modify, sublicense or distribute the Program is 184void, and will automatically terminate your rights under this License. 185However, parties who have received copies, or rights, from you under 186this License will not have their licenses terminated so long as such 187parties remain in full compliance. 188 189 5. You are not required to accept this License, since you have not 190signed it. However, nothing else grants you permission to modify or 191distribute the Program or its derivative works. These actions are 192prohibited by law if you do not accept this License. Therefore, by 193modifying or distributing the Program (or any work based on the 194Program), you indicate your acceptance of this License to do so, and 195all its terms and conditions for copying, distributing or modifying 196the Program or works based on it. 197 198 6. Each time you redistribute the Program (or any work based on the 199Program), the recipient automatically receives a license from the 200original licensor to copy, distribute or modify the Program subject to 201these terms and conditions. You may not impose any further 202restrictions on the recipients' exercise of the rights granted herein. 203You are not responsible for enforcing compliance by third parties to 204this License. 205 206 7. If, as a consequence of a court judgment or allegation of patent 207infringement or for any other reason (not limited to patent issues), 208conditions are imposed on you (whether by court order, agreement or 209otherwise) that contradict the conditions of this License, they do not 210excuse you from the conditions of this License. If you cannot 211distribute so as to satisfy simultaneously your obligations under this 212License and any other pertinent obligations, then as a consequence you 213may not distribute the Program at all. For example, if a patent 214license would not permit royalty-free redistribution of the Program by 215all those who receive copies directly or indirectly through you, then 216the only way you could satisfy both it and this License would be to 217refrain entirely from distribution of the Program. 218 219If any portion of this section is held invalid or unenforceable under 220any particular circumstance, the balance of the section is intended to 221apply and the section as a whole is intended to apply in other 222circumstances. 223 224It is not the purpose of this section to induce you to infringe any 225patents or other property right claims or to contest validity of any 226such claims; this section has the sole purpose of protecting the 227integrity of the free software distribution system, which is 228implemented by public license practices. Many people have made 229generous contributions to the wide range of software distributed 230through that system in reliance on consistent application of that 231system; it is up to the author/donor to decide if he or she is willing 232to distribute software through any other system and a licensee cannot 233impose that choice. 234 235This section is intended to make thoroughly clear what is believed to 236be a consequence of the rest of this License. 237 238 8. If the distribution and/or use of the Program is restricted in 239certain countries either by patents or by copyrighted interfaces, the 240original copyright holder who places the Program under this License 241may add an explicit geographical distribution limitation excluding 242those countries, so that distribution is permitted only in or among 243countries not thus excluded. In such case, this License incorporates 244the limitation as if written in the body of this License. 245 246 9. The Free Software Foundation may publish revised and/or new versions 247of the General Public License from time to time. Such new versions will 248be similar in spirit to the present version, but may differ in detail to 249address new problems or concerns. 250 251Each version is given a distinguishing version number. If the Program 252specifies a version number of this License which applies to it and "any 253later version", you have the option of following the terms and conditions 254either of that version or of any later version published by the Free 255Software Foundation. If the Program does not specify a version number of 256this License, you may choose any version ever published by the Free Software 257Foundation. 258 259 10. If you wish to incorporate parts of the Program into other free 260programs whose distribution conditions are different, write to the author 261to ask for permission. For software which is copyrighted by the Free 262Software Foundation, write to the Free Software Foundation; we sometimes 263make exceptions for this. Our decision will be guided by the two goals 264of preserving the free status of all derivatives of our free software and 265of promoting the sharing and reuse of software generally. 266 267 NO WARRANTY 268 269 11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY 270FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN 271OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES 272PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED 273OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 274MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS 275TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE 276PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, 277REPAIR OR CORRECTION. 278 279 12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 280WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR 281REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, 282INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING 283OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED 284TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY 285YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER 286PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE 287POSSIBILITY OF SUCH DAMAGES. 288 289 END OF TERMS AND CONDITIONS 290