1GNU General Public License, version 2 (GPL-2.0) 2 3The GNU General Public License (GPL-2.0) 4 5Version 2, June 1991 6 7Copyright (C) 1989, 1991 Free Software Foundation, Inc. 8 959 Temple Place, Suite 330, Boston, MA 02111-1307 USA 10 11Everyone is permitted to copy and distribute verbatim copies 12 13of this license document, but changing it is not allowed. 14 15Preamble 16 17The licenses for most software are designed to take away your freedom to share 18and change it. By contrast, the GNU General Public License is intended to 19guarantee your freedom to share and change free software--to make sure the 20software is free for all its users. This General Public License applies to 21most of the Free Software Foundation's software and to any other program whose 22authors commit to using it. (Some other Free Software Foundation software is 23covered by the GNU Library General Public License instead.) You can apply it 24to your programs, too. 25 26When we speak of free software, we are referring to freedom, not price. Our 27General Public Licenses are designed to make sure that you have the freedom to 28distribute copies of free software (and charge for this service if you wish), 29that you receive source code or can get it if you want it, that you can change 30the software or use pieces of it in new free programs; and that you know you 31can do these things. 32 33To protect your rights, we need to make restrictions that forbid anyone to 34deny you these rights or to ask you to surrender the rights. These 35restrictions translate to certain responsibilities for you if you distribute 36copies of the software, or if you modify it. 37 38For example, if you distribute copies of such a program, whether gratis or for 39a fee, you must give the recipients all the rights that you have. You must 40make sure that they, too, receive or can get the source code. And you must 41show them these terms so they know their rights. 42 43We protect your rights with two steps: (1) copyright the software, and (2) 44offer you this license which gives you legal permission to copy, distribute 45and/or modify the software. 46 47Also, for each author's protection and ours, we want to make certain that 48everyone understands that there is no warranty for this free software. If the 49software is modified by someone else and passed on, we want its recipients to 50know that what they have is not the original, so that any problems introduced 51by others will not reflect on the original authors' reputations. 52 53Finally, any free program is threatened constantly by software patents. We 54wish to avoid the danger that redistributors of a free program will 55individually obtain patent licenses, in effect making the program proprietary. 56To prevent this, we have made it clear that any patent must be licensed for 57everyone's free use or not licensed at all. 58 59The precise terms and conditions for copying, distribution and modification 60follow. 61 62TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 63 640\. This License applies to any program or other work which contains a notice 65placed by the copyright holder saying it may be distributed under the terms of 66this General Public License. The "Program", below, refers to any such program 67or work, and a "work based on the Program" means either the Program or any 68derivative work under copyright law: that is to say, a work containing the 69Program or a portion of it, either verbatim or with modifications and/or 70translated into another language. (Hereinafter, translation is included 71without limitation in the term "modification".) Each licensee is addressed as 72"you". 73 74Activities other than copying, distribution and modification are not covered 75by this License; they are outside its scope. The act of running the Program is 76not restricted, and the output from the Program is covered only if its 77contents constitute a work based on the Program (independent of having been 78made by running the Program). Whether that is true depends on what the Program 79does. 80 811\. You may copy and distribute verbatim copies of the Program's source code 82as you receive it, in any medium, provided that you conspicuously and 83appropriately publish on each copy an appropriate copyright notice and 84disclaimer of warranty; keep intact all the notices that refer to this License 85and to the absence of any warranty; and give any other recipients of the 86Program a copy of this License along with the Program. 87 88You may charge a fee for the physical act of transferring a copy, and you may 89at your option offer warranty protection in exchange for a fee. 90 912\. You may modify your copy or copies of the Program or any portion of it, 92thus forming a work based on the Program, and copy and distribute such 93modifications or work under the terms of Section 1 above, provided that you 94also meet all of these conditions: 95 96a) You must cause the modified files to carry prominent notices stating that 97you changed the files and the date of any change. 98 99b) You must cause any work that you distribute or publish, that in whole or in 100part contains or is derived from the Program or any part thereof, to be 101licensed as a whole at no charge to all third parties under the terms of this 102License. 103 104c) If the modified program normally reads commands interactively when run, you 105must cause it, when started running for such interactive use in the most 106ordinary way, to print or display an announcement including an appropriate 107copyright notice and a notice that there is no warranty (or else, saying that 108you provide a warranty) and that users may redistribute the program under 109these conditions, and telling the user how to view a copy of this License. 110(Exception: if the Program itself is interactive but does not normally print 111such an announcement, your work based on the Program is not required to print 112an announcement.) 113 114These requirements apply to the modified work as a whole. If identifiable 115sections of that work are not derived from the Program, and can be reasonably 116considered independent and separate works in themselves, then this License, 117and its terms, do not apply to those sections when you distribute them as 118separate works. But when you distribute the same sections as part of a whole 119which is a work based on the Program, the distribution of the whole must be on 120the terms of this License, whose permissions for other licensees extend to the 121entire whole, and thus to each and every part regardless of who wrote it. 122 123Thus, it is not the intent of this section to claim rights or contest your 124rights to work written entirely by you; rather, the intent is to exercise the 125right to control the distribution of derivative or collective works based on 126the Program. 127 128In addition, mere aggregation of another work not based on the Program with 129the Program (or with a work based on the Program) on a volume of a storage or 130distribution medium does not bring the other work under the scope of this 131License. 132 1333\. You may copy and distribute the Program (or a work based on it, under 134Section 2) in object code or executable form under the terms of Sections 1 and 1352 above provided that you also do one of the following: 136 137a) Accompany it with the complete corresponding machine-readable source code, 138which must be distributed under the terms of Sections 1 and 2 above on a 139medium customarily used for software interchange; or, 140 141b) Accompany it with a written offer, valid for at least three years, to give 142any third party, for a charge no more than your cost of physically performing 143source distribution, a complete machine-readable copy of the corresponding 144source code, to be distributed under the terms of Sections 1 and 2 above on a 145medium customarily used for software interchange; or, 146 147c) Accompany it with the information you received as to the offer to 148distribute corresponding source code. (This alternative is allowed only for 149noncommercial distribution and only if you received the program in object code 150or executable form with such an offer, in accord with Subsection b above.) 151 152The source code for a work means the preferred form of the work for making 153modifications to it. For an executable work, complete source code means all 154the source code for all modules it contains, plus any associated interface 155definition files, plus the scripts used to control compilation and 156installation of the executable. However, as a special exception, the source 157code distributed need not include anything that is normally distributed (in 158either source or binary form) with the major components (compiler, kernel, and 159so on) of the operating system on which the executable runs, unless that 160component itself accompanies the executable. 161 162If distribution of executable or object code is made by offering access to 163copy from a designated place, then offering equivalent access to copy the 164source code from the same place counts as distribution of the source code, 165even though third parties are not compelled to copy the source along with the 166object code. 167 1684\. You may not copy, modify, sublicense, or distribute the Program except as 169expressly provided under this License. Any attempt otherwise to copy, modify, 170sublicense or distribute the Program is void, and will automatically terminate 171your rights under this License. However, parties who have received copies, or 172rights, from you under this License will not have their licenses terminated so 173long as such parties remain in full compliance. 174 1755\. You are not required to accept this License, since you have not signed it. 176However, nothing else grants you permission to modify or distribute the 177Program or its derivative works. These actions are prohibited by law if you do 178not accept this License. Therefore, by modifying or distributing the Program 179(or any work based on the Program), you indicate your acceptance of this 180License to do so, and all its terms and conditions for copying, distributing 181or modifying the Program or works based on it. 182 1836\. Each time you redistribute the Program (or any work based on the Program), 184the recipient automatically receives a license from the original licensor to 185copy, distribute or modify the Program subject to these terms and conditions. 186You may not impose any further restrictions on the recipients' exercise of the 187rights granted herein. You are not responsible for enforcing compliance by 188third parties to this License. 189 1907\. If, as a consequence of a court judgment or allegation of patent 191infringement or for any other reason (not limited to patent issues), 192conditions are imposed on you (whether by court order, agreement or otherwise) 193that contradict the conditions of this License, they do not excuse you from 194the conditions of this License. If you cannot distribute so as to satisfy 195simultaneously your obligations under this License and any other pertinent 196obligations, then as a consequence you may not distribute the Program at all. 197For example, if a patent license would not permit royalty-free redistribution 198of the Program by all those who receive copies directly or indirectly through 199you, then the only way you could satisfy both it and this License would be to 200refrain entirely from distribution of the Program. 201 202If any portion of this section is held invalid or unenforceable under any 203particular circumstance, the balance of the section is intended to apply and 204the section as a whole is intended to apply in other circumstances. 205 206It is not the purpose of this section to induce you to infringe any patents or 207other property right claims or to contest validity of any such claims; this 208section has the sole purpose of protecting the integrity of the free software 209distribution system, which is implemented by public license practices. Many 210people have made generous contributions to the wide range of software 211distributed through that system in reliance on consistent application of that 212system; it is up to the author/donor to decide if he or she is willing to 213distribute software through any other system and a licensee cannot impose that 214choice. 215 216This section is intended to make thoroughly clear what is believed to be a 217consequence of the rest of this License. 218 2198\. If the distribution and/or use of the Program is restricted in certain 220countries either by patents or by copyrighted interfaces, the original 221copyright holder who places the Program under this License may add an explicit 222geographical distribution limitation excluding those countries, so that 223distribution is permitted only in or among countries not thus excluded. In 224such case, this License incorporates the limitation as if written in the body 225of this License. 226 2279\. The Free Software Foundation may publish revised and/or new versions of 228the General Public License from time to time. Such new versions will be 229similar in spirit to the present version, but may differ in detail to address 230new problems or concerns. 231 232Each version is given a distinguishing version number. If the Program 233specifies a version number of this License which applies to it and "any later 234version", you have the option of following the terms and conditions either of 235that version or of any later version published by the Free Software 236Foundation. If the Program does not specify a version number of this License, 237you may choose any version ever published by the Free Software Foundation. 238 23910\. If you wish to incorporate parts of the Program into other free programs 240whose distribution conditions are different, write to the author to ask for 241permission. For software which is copyrighted by the Free Software Foundation, 242write to the Free Software Foundation; we sometimes make exceptions for this. 243Our decision will be guided by the two goals of preserving the free status of 244all derivatives of our free software and of promoting the sharing and reuse of 245software generally. 246 247NO WARRANTY 248 24911\. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR 250THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE 251STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE 252PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, 253INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 254FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND 255PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, 256YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. 257 25812\. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 259WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR 260REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, 261INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING 262OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO 263LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR 264THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), 265EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH 266DAMAGES. 267 268END OF TERMS AND CONDITIONS 269 270How to Apply These Terms to Your New Programs 271 272If you develop a new program, and you want it to be of the greatest possible 273use to the public, the best way to achieve this is to make it free software 274which everyone can redistribute and change under these terms. 275 276To do so, attach the following notices to the program. It is safest to attach 277them to the start of each source file to most effectively convey the exclusion 278of warranty; and each file should have at least the "copyright" line and a 279pointer to where the full notice is found. 280 281One line to give the program's name and a brief idea of what it does. 282 283Copyright (C) <year> <name of author> 284 285This program is free software; you can redistribute it and/or modify it under 286the terms of the GNU General Public License as published by the Free Software 287Foundation; either version 2 of the License, or (at your option) any later 288version. 289 290This program is distributed in the hope that it will be useful, but WITHOUT 291ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 292FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. 293 294You should have received a copy of the GNU General Public License along with 295this program; if not, write to the Free Software Foundation, Inc., 59 Temple 296Place, Suite 330, Boston, MA 02111-1307 USA 297 298Also add information on how to contact you by electronic and paper mail. 299 300If the program is interactive, make it output a short notice like this when it 301starts in an interactive mode: 302 303Gnomovision version 69, Copyright (C) year name of author Gnomovision comes 304with ABSOLUTELY NO WARRANTY; for details type `show w'. This is free software, 305and you are welcome to redistribute it under certain conditions; type `show c' 306for details. 307 308The hypothetical commands `show w' and `show c' should show the appropriate 309parts of the General Public License. Of course, the commands you use may be 310called something other than `show w' and `show c'; they could even be mouse- 311clicks or menu items--whatever suits your program. 312 313You should also get your employer (if you work as a programmer) or your 314school, if any, to sign a "copyright disclaimer" for the program, if 315necessary. Here is a sample; alter the names: 316 317Yoyodyne, Inc., hereby disclaims all copyright interest in the program 318`Gnomovision' (which makes passes at compilers) written by James Hacker. 319 320signature of Ty Coon, 1 April 1989 321 322Ty Coon, President of Vice 323 324This General Public License does not permit incorporating your program into 325proprietary programs. If your program is a subroutine library, you may 326consider it more useful to permit linking proprietary applications with the 327library. If this is what you want to do, use the GNU Library General Public 328License instead of this License. 329 330hetical commands `show w' and `show c' should show the appropriate 331parts of the General Public License. Of course, the commands you use may be 332called something other than `show w' and `show c'; they could even be mouse- 333clicks or menu items--whatever suits your program. 334 335You should also get your employer (if you work as a programmer) or your 336school, if any, to sign a "copyright disclaimer" for the program. 337