1@node GNU GPL 2@appendixsec GNU GENERAL PUBLIC LICENSE 3@cindex GPL, GNU General Public License 4@cindex License, GNU GPL 5@center Version 2, June 1991 6 7@c This file is intended to be included in another file. 8 9@display 10Copyright @copyright{} 1989, 1991 Free Software Foundation, Inc. 1151 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA 12 13Everyone is permitted to copy and distribute verbatim copies 14of this license document, but changing it is not allowed. 15@end display 16 17@unnumberedsubsec Preamble 18 19 The licenses for most software are designed to take away your 20freedom to share and change it. By contrast, the GNU General Public 21License is intended to guarantee your freedom to share and change free 22software---to make sure the software is free for all its users. This 23General Public License applies to most of the Free Software 24Foundation's software and to any other program whose authors commit to 25using it. (Some other Free Software Foundation software is covered by 26the GNU Library General Public License instead.) You can apply it to 27your programs, too. 28 29 When we speak of free software, we are referring to freedom, not 30price. Our General Public Licenses are designed to make sure that you 31have the freedom to distribute copies of free software (and charge for 32this service if you wish), that you receive source code or can get it 33if you want it, that you can change the software or use pieces of it 34in new free programs; and that you know you can do these things. 35 36 To protect your rights, we need to make restrictions that forbid 37anyone to deny you these rights or to ask you to surrender the rights. 38These restrictions translate to certain responsibilities for you if you 39distribute copies of the software, or if you modify it. 40 41 For example, if you distribute copies of such a program, whether 42gratis or for a fee, you must give the recipients all the rights that 43you have. You must make sure that they, too, receive or can get the 44source code. And you must show them these terms so they know their 45rights. 46 47 We protect your rights with two steps: (1) copyright the software, and 48(2) offer you this license which gives you legal permission to copy, 49distribute and/or modify the software. 50 51 Also, for each author's protection and ours, we want to make certain 52that everyone understands that there is no warranty for this free 53software. If the software is modified by someone else and passed on, we 54want its recipients to know that what they have is not the original, so 55that any problems introduced by others will not reflect on the original 56authors' reputations. 57 58 Finally, any free program is threatened constantly by software 59patents. We wish to avoid the danger that redistributors of a free 60program will individually obtain patent licenses, in effect making the 61program proprietary. To prevent this, we have made it clear that any 62patent must be licensed for everyone's free use or not licensed at all. 63 64 The precise terms and conditions for copying, distribution and 65modification follow. 66 67@iftex 68@unnumberedsubsec TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 69@end iftex 70@ifinfo 71@center TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 72 73@end ifinfo 74 75@enumerate 0 76@item 77This License applies to any program or other work which contains 78a notice placed by the copyright holder saying it may be distributed 79under the terms of this General Public License. The ``Program'', below, 80refers to any such program or work, and a ``work based on the Program'' 81means either the Program or any derivative work under copyright law: 82that is to say, a work containing the Program or a portion of it, 83either verbatim or with modifications and/or translated into another 84language. (Hereinafter, translation is included without limitation in 85the term ``modification''.) Each licensee is addressed as ``you''. 86 87Activities other than copying, distribution and modification are not 88covered by this License; they are outside its scope. The act of 89running the Program is not restricted, and the output from the Program 90is covered only if its contents constitute a work based on the 91Program (independent of having been made by running the Program). 92Whether that is true depends on what the Program does. 93 94@item 95You may copy and distribute verbatim copies of the Program's 96source code as you receive it, in any medium, provided that you 97conspicuously and appropriately publish on each copy an appropriate 98copyright notice and disclaimer of warranty; keep intact all the 99notices that refer to this License and to the absence of any warranty; 100and give any other recipients of the Program a copy of this License 101along with the Program. 102 103You may charge a fee for the physical act of transferring a copy, and 104you may at your option offer warranty protection in exchange for a fee. 105 106@item 107You may modify your copy or copies of the Program or any portion 108of it, thus forming a work based on the Program, and copy and 109distribute such modifications or work under the terms of Section 1 110above, provided that you also meet all of these conditions: 111 112@enumerate a 113@item 114You must cause the modified files to carry prominent notices 115stating that you changed the files and the date of any change. 116 117@item 118You must cause any work that you distribute or publish, that in 119whole or in part contains or is derived from the Program or any 120part thereof, to be licensed as a whole at no charge to all third 121parties under the terms of this License. 122 123@item 124If the modified program normally reads commands interactively 125when run, you must cause it, when started running for such 126interactive use in the most ordinary way, to print or display an 127announcement including an appropriate copyright notice and a 128notice that there is no warranty (or else, saying that you provide 129a warranty) and that users may redistribute the program under 130these conditions, and telling the user how to view a copy of this 131License. (Exception: if the Program itself is interactive but 132does not normally print such an announcement, your work based on 133the Program is not required to print an announcement.) 134@end enumerate 135 136These requirements apply to the modified work as a whole. If 137identifiable sections of that work are not derived from the Program, 138and can be reasonably considered independent and separate works in 139themselves, then this License, and its terms, do not apply to those 140sections when you distribute them as separate works. But when you 141distribute the same sections as part of a whole which is a work based 142on the Program, the distribution of the whole must be on the terms of 143this License, whose permissions for other licensees extend to the 144entire whole, and thus to each and every part regardless of who wrote it. 145 146Thus, it is not the intent of this section to claim rights or contest 147your rights to work written entirely by you; rather, the intent is to 148exercise the right to control the distribution of derivative or 149collective works based on the Program. 150 151In addition, mere aggregation of another work not based on the Program 152with the Program (or with a work based on the Program) on a volume of 153a storage or distribution medium does not bring the other work under 154the scope of this License. 155 156@item 157You may copy and distribute the Program (or a work based on it, 158under Section 2) in object code or executable form under the terms of 159Sections 1 and 2 above provided that you also do one of the following: 160 161@enumerate a 162@item 163Accompany it with the complete corresponding machine-readable 164source code, which must be distributed under the terms of Sections 1651 and 2 above on a medium customarily used for software interchange; or, 166 167@item 168Accompany it with a written offer, valid for at least three 169years, to give any third party, for a charge no more than your 170cost of physically performing source distribution, a complete 171machine-readable copy of the corresponding source code, to be 172distributed under the terms of Sections 1 and 2 above on a medium 173customarily used for software interchange; or, 174 175@item 176Accompany it with the information you received as to the offer 177to distribute corresponding source code. (This alternative is 178allowed only for noncommercial distribution and only if you 179received the program in object code or executable form with such 180an offer, in accord with Subsection b above.) 181@end enumerate 182 183The source code for a work means the preferred form of the work for 184making modifications to it. For an executable work, complete source 185code means all the source code for all modules it contains, plus any 186associated interface definition files, plus the scripts used to 187control compilation and installation of the executable. However, as a 188special exception, the source code distributed need not include 189anything that is normally distributed (in either source or binary 190form) with the major components (compiler, kernel, and so on) of the 191operating system on which the executable runs, unless that component 192itself accompanies the executable. 193 194If distribution of executable or object code is made by offering 195access to copy from a designated place, then offering equivalent 196access to copy the source code from the same place counts as 197distribution of the source code, even though third parties are not 198compelled to copy the source along with the object code. 199 200@item 201You may not copy, modify, sublicense, or distribute the Program 202except as expressly provided under this License. Any attempt 203otherwise to copy, modify, sublicense or distribute the Program is 204void, and will automatically terminate your rights under this License. 205However, parties who have received copies, or rights, from you under 206this License will not have their licenses terminated so long as such 207parties remain in full compliance. 208 209@item 210You are not required to accept this License, since you have not 211signed it. However, nothing else grants you permission to modify or 212distribute the Program or its derivative works. These actions are 213prohibited by law if you do not accept this License. Therefore, by 214modifying or distributing the Program (or any work based on the 215Program), you indicate your acceptance of this License to do so, and 216all its terms and conditions for copying, distributing or modifying 217the Program or works based on it. 218 219@item 220Each time you redistribute the Program (or any work based on the 221Program), the recipient automatically receives a license from the 222original licensor to copy, distribute or modify the Program subject to 223these terms and conditions. You may not impose any further 224restrictions on the recipients' exercise of the rights granted herein. 225You are not responsible for enforcing compliance by third parties to 226this License. 227 228@item 229If, as a consequence of a court judgment or allegation of patent 230infringement or for any other reason (not limited to patent issues), 231conditions are imposed on you (whether by court order, agreement or 232otherwise) that contradict the conditions of this License, they do not 233excuse you from the conditions of this License. If you cannot 234distribute so as to satisfy simultaneously your obligations under this 235License and any other pertinent obligations, then as a consequence you 236may not distribute the Program at all. For example, if a patent 237license would not permit royalty-free redistribution of the Program by 238all those who receive copies directly or indirectly through you, then 239the only way you could satisfy both it and this License would be to 240refrain entirely from distribution of the Program. 241 242If any portion of this section is held invalid or unenforceable under 243any particular circumstance, the balance of the section is intended to 244apply and the section as a whole is intended to apply in other 245circumstances. 246 247It is not the purpose of this section to induce you to infringe any 248patents or other property right claims or to contest validity of any 249such claims; this section has the sole purpose of protecting the 250integrity of the free software distribution system, which is 251implemented by public license practices. Many people have made 252generous contributions to the wide range of software distributed 253through that system in reliance on consistent application of that 254system; it is up to the author/donor to decide if he or she is willing 255to distribute software through any other system and a licensee cannot 256impose that choice. 257 258This section is intended to make thoroughly clear what is believed to 259be a consequence of the rest of this License. 260 261@item 262If the distribution and/or use of the Program is restricted in 263certain countries either by patents or by copyrighted interfaces, the 264original copyright holder who places the Program under this License 265may add an explicit geographical distribution limitation excluding 266those countries, so that distribution is permitted only in or among 267countries not thus excluded. In such case, this License incorporates 268the limitation as if written in the body of this License. 269 270@item 271The Free Software Foundation may publish revised and/or new versions 272of the General Public License from time to time. Such new versions will 273be similar in spirit to the present version, but may differ in detail to 274address new problems or concerns. 275 276Each version is given a distinguishing version number. If the Program 277specifies a version number of this License which applies to it and ``any 278later version'', you have the option of following the terms and conditions 279either of that version or of any later version published by the Free 280Software Foundation. If the Program does not specify a version number of 281this License, you may choose any version ever published by the Free Software 282Foundation. 283 284@item 285If you wish to incorporate parts of the Program into other free 286programs whose distribution conditions are different, write to the author 287to ask for permission. For software which is copyrighted by the Free 288Software Foundation, write to the Free Software Foundation; we sometimes 289make exceptions for this. Our decision will be guided by the two goals 290of preserving the free status of all derivatives of our free software and 291of promoting the sharing and reuse of software generally. 292 293@iftex 294@heading NO WARRANTY 295@end iftex 296@ifinfo 297@center NO WARRANTY 298 299@end ifinfo 300 301@item 302BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY 303FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN 304OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES 305PROVIDE THE PROGRAM ``AS IS'' WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED 306OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 307MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS 308TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE 309PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, 310REPAIR OR CORRECTION. 311 312@item 313IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 314WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR 315REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, 316INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING 317OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED 318TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY 319YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER 320PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE 321POSSIBILITY OF SUCH DAMAGES. 322@end enumerate 323 324@iftex 325@heading END OF TERMS AND CONDITIONS 326@end iftex 327@ifinfo 328@center END OF TERMS AND CONDITIONS 329 330@end ifinfo 331 332@page 333@unnumberedsubsec Appendix: How to Apply These Terms to Your New Programs 334 335 If you develop a new program, and you want it to be of the greatest 336possible use to the public, the best way to achieve this is to make it 337free software which everyone can redistribute and change under these terms. 338 339 To do so, attach the following notices to the program. It is safest 340to attach them to the start of each source file to most effectively 341convey the exclusion of warranty; and each file should have at least 342the ``copyright'' line and a pointer to where the full notice is found. 343 344@smallexample 345@var{one line to give the program's name and a brief idea of what it does.} 346Copyright (C) @var{yyyy} @var{name of author} 347 348This program is free software; you can redistribute it and/or modify 349it under the terms of the GNU General Public License as published by 350the Free Software Foundation; either version 2 of the License, or 351(at your option) any later version. 352 353This program is distributed in the hope that it will be useful, 354but WITHOUT ANY WARRANTY; without even the implied warranty of 355MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 356GNU General Public License for more details. 357 358You should have received a copy of the GNU General Public License 359along with this program; if not, write to the Free Software 360Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 361@end smallexample 362 363Also add information on how to contact you by electronic and paper mail. 364 365If the program is interactive, make it output a short notice like this 366when it starts in an interactive mode: 367 368@smallexample 369Gnomovision version 69, Copyright (C) 19@var{yy} @var{name of author} 370Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 371This is free software, and you are welcome to redistribute it 372under certain conditions; type `show c' for details. 373@end smallexample 374 375The hypothetical commands @samp{show w} and @samp{show c} should show 376the appropriate parts of the General Public License. Of course, the 377commands you use may be called something other than @samp{show w} and 378@samp{show c}; they could even be mouse-clicks or menu items---whatever 379suits your program. 380 381You should also get your employer (if you work as a programmer) or your 382school, if any, to sign a ``copyright disclaimer'' for the program, if 383necessary. Here is a sample; alter the names: 384 385@example 386Yoyodyne, Inc., hereby disclaims all copyright interest in the program 387`Gnomovision' (which makes passes at compilers) written by James Hacker. 388 389@var{signature of Ty Coon}, 1 April 1989 390Ty Coon, President of Vice 391@end example 392 393This General Public License does not permit incorporating your program into 394proprietary programs. If your program is a subroutine library, you may 395consider it more useful to permit linking proprietary applications with the 396library. If this is what you want to do, use the GNU Library General 397Public License instead of this License. 398