1@c The GNU General Public License. 2@center Version 2, June 1991 3 4@c This file is intended to be included within another document, 5@c hence no sectioning command or @node. 6 7@display 8Copyright @copyright{} 1989, 1991 Free Software Foundation, Inc. 951 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA 10 11Everyone is permitted to copy and distribute verbatim copies 12of this license document, but changing it is not allowed. 13@end display 14 15@heading Preamble 16 17 The licenses for most software are designed to take away your 18freedom to share and change it. By contrast, the GNU General Public 19License is intended to guarantee your freedom to share and change free 20software---to make sure the software is free for all its users. This 21General Public License applies to most of the Free Software 22Foundation's software and to any other program whose authors commit to 23using it. (Some other Free Software Foundation software is covered by 24the GNU Lesser General Public License instead.) You can apply it to 25your programs, too. 26 27 When we speak of free software, we are referring to freedom, not 28price. Our General Public Licenses are designed to make sure that you 29have the freedom to distribute copies of free software (and charge for 30this service if you wish), that you receive source code or can get it 31if you want it, that you can change the software or use pieces of it 32in new free programs; and that you know you can do these things. 33 34 To protect your rights, we need to make restrictions that forbid 35anyone to deny you these rights or to ask you to surrender the rights. 36These restrictions translate to certain responsibilities for you if you 37distribute copies of the software, or if you modify it. 38 39 For example, if you distribute copies of such a program, whether 40gratis or for a fee, you must give the recipients all the rights that 41you have. You must make sure that they, too, receive or can get the 42source code. And you must show them these terms so they know their 43rights. 44 45 We protect your rights with two steps: (1) copyright the software, and 46(2) offer you this license which gives you legal permission to copy, 47distribute and/or modify the software. 48 49 Also, for each author's protection and ours, we want to make certain 50that everyone understands that there is no warranty for this free 51software. If the software is modified by someone else and passed on, we 52want its recipients to know that what they have is not the original, so 53that any problems introduced by others will not reflect on the original 54authors' reputations. 55 56 Finally, any free program is threatened constantly by software 57patents. We wish to avoid the danger that redistributors of a free 58program will individually obtain patent licenses, in effect making the 59program proprietary. To prevent this, we have made it clear that any 60patent must be licensed for everyone's free use or not licensed at all. 61 62 The precise terms and conditions for copying, distribution and 63modification follow. 64 65@heading TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 66 67@enumerate 0 68@item 69This License applies to any program or other work which contains 70a notice placed by the copyright holder saying it may be distributed 71under the terms of this General Public License. The ``Program'', below, 72refers to any such program or work, and a ``work based on the Program'' 73means either the Program or any derivative work under copyright law: 74that is to say, a work containing the Program or a portion of it, 75either verbatim or with modifications and/or translated into another 76language. (Hereinafter, translation is included without limitation in 77the term ``modification''.) Each licensee is addressed as ``you''. 78 79Activities other than copying, distribution and modification are not 80covered by this License; they are outside its scope. The act of 81running the Program is not restricted, and the output from the Program 82is covered only if its contents constitute a work based on the 83Program (independent of having been made by running the Program). 84Whether that is true depends on what the Program does. 85 86@item 87You may copy and distribute verbatim copies of the Program's 88source code as you receive it, in any medium, provided that you 89conspicuously and appropriately publish on each copy an appropriate 90copyright notice and disclaimer of warranty; keep intact all the 91notices that refer to this License and to the absence of any warranty; 92and give any other recipients of the Program a copy of this License 93along with the Program. 94 95You may charge a fee for the physical act of transferring a copy, and 96you may at your option offer warranty protection in exchange for a fee. 97 98@item 99You 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@enumerate a 105@item 106You must cause the modified files to carry prominent notices 107stating that you changed the files and the date of any change. 108 109@item 110You must cause any work that you distribute or publish, that in 111whole or in part contains or is derived from the Program or any 112part thereof, to be licensed as a whole at no charge to all third 113parties under the terms of this License. 114 115@item 116If the modified program normally reads commands interactively 117when run, you must cause it, when started running for such 118interactive use in the most ordinary way, to print or display an 119announcement including an appropriate copyright notice and a 120notice that there is no warranty (or else, saying that you provide 121a warranty) and that users may redistribute the program under 122these conditions, and telling the user how to view a copy of this 123License. (Exception: if the Program itself is interactive but 124does not normally print such an announcement, your work based on 125the Program is not required to print an announcement.) 126@end enumerate 127 128These requirements apply to the modified work as a whole. If 129identifiable sections of that work are not derived from the Program, 130and can be reasonably considered independent and separate works in 131themselves, then this License, and its terms, do not apply to those 132sections when you distribute them as separate works. But when you 133distribute the same sections as part of a whole which is a work based 134on the Program, the distribution of the whole must be on the terms of 135this License, whose permissions for other licensees extend to the 136entire whole, and thus to each and every part regardless of who wrote it. 137 138Thus, it is not the intent of this section to claim rights or contest 139your rights to work written entirely by you; rather, the intent is to 140exercise the right to control the distribution of derivative or 141collective works based on the Program. 142 143In addition, mere aggregation of another work not based on the Program 144with the Program (or with a work based on the Program) on a volume of 145a storage or distribution medium does not bring the other work under 146the scope of this License. 147 148@item 149You may copy and distribute the Program (or a work based on it, 150under Section 2) in object code or executable form under the terms of 151Sections 1 and 2 above provided that you also do one of the following: 152 153@enumerate a 154@item 155Accompany it with the complete corresponding machine-readable 156source code, which must be distributed under the terms of Sections 1571 and 2 above on a medium customarily used for software interchange; or, 158 159@item 160Accompany it with a written offer, valid for at least three 161years, to give any third party, for a charge no more than your 162cost of physically performing source distribution, a complete 163machine-readable copy of the corresponding source code, to be 164distributed under the terms of Sections 1 and 2 above on a medium 165customarily used for software interchange; or, 166 167@item 168Accompany it with the information you received as to the offer 169to distribute corresponding source code. (This alternative is 170allowed only for noncommercial distribution and only if you 171received the program in object code or executable form with such 172an offer, in accord with Subsection b above.) 173@end enumerate 174 175The source code for a work means the preferred form of the work for 176making modifications to it. For an executable work, complete source 177code means all the source code for all modules it contains, plus any 178associated interface definition files, plus the scripts used to 179control compilation and installation of the executable. However, as a 180special exception, the source code distributed need not include 181anything that is normally distributed (in either source or binary 182form) with the major components (compiler, kernel, and so on) of the 183operating system on which the executable runs, unless that component 184itself accompanies the executable. 185 186If distribution of executable or object code is made by offering 187access to copy from a designated place, then offering equivalent 188access to copy the source code from the same place counts as 189distribution of the source code, even though third parties are not 190compelled to copy the source along with the object code. 191 192@item 193You may not copy, modify, sublicense, or distribute the Program 194except as expressly provided under this License. Any attempt 195otherwise to copy, modify, sublicense or distribute the Program is 196void, and will automatically terminate your rights under this License. 197However, parties who have received copies, or rights, from you under 198this License will not have their licenses terminated so long as such 199parties remain in full compliance. 200 201@item 202You are not required to accept this License, since you have not 203signed it. However, nothing else grants you permission to modify or 204distribute the Program or its derivative works. These actions are 205prohibited by law if you do not accept this License. Therefore, by 206modifying or distributing the Program (or any work based on the 207Program), you indicate your acceptance of this License to do so, and 208all its terms and conditions for copying, distributing or modifying 209the Program or works based on it. 210 211@item 212Each time you redistribute the Program (or any work based on the 213Program), the recipient automatically receives a license from the 214original licensor to copy, distribute or modify the Program subject to 215these terms and conditions. You may not impose any further 216restrictions on the recipients' exercise of the rights granted herein. 217You are not responsible for enforcing compliance by third parties to 218this License. 219 220@item 221If, as a consequence of a court judgment or allegation of patent 222infringement or for any other reason (not limited to patent issues), 223conditions are imposed on you (whether by court order, agreement or 224otherwise) that contradict the conditions of this License, they do not 225excuse you from the conditions of this License. If you cannot 226distribute so as to satisfy simultaneously your obligations under this 227License and any other pertinent obligations, then as a consequence you 228may not distribute the Program at all. For example, if a patent 229license would not permit royalty-free redistribution of the Program by 230all those who receive copies directly or indirectly through you, then 231the only way you could satisfy both it and this License would be to 232refrain entirely from distribution of the Program. 233 234If any portion of this section is held invalid or unenforceable under 235any particular circumstance, the balance of the section is intended to 236apply and the section as a whole is intended to apply in other 237circumstances. 238 239It is not the purpose of this section to induce you to infringe any 240patents or other property right claims or to contest validity of any 241such claims; this section has the sole purpose of protecting the 242integrity of the free software distribution system, which is 243implemented by public license practices. Many people have made 244generous contributions to the wide range of software distributed 245through that system in reliance on consistent application of that 246system; it is up to the author/donor to decide if he or she is willing 247to distribute software through any other system and a licensee cannot 248impose that choice. 249 250This section is intended to make thoroughly clear what is believed to 251be a consequence of the rest of this License. 252 253@item 254If the distribution and/or use of the Program is restricted in 255certain countries either by patents or by copyrighted interfaces, the 256original copyright holder who places the Program under this License 257may add an explicit geographical distribution limitation excluding 258those countries, so that distribution is permitted only in or among 259countries not thus excluded. In such case, this License incorporates 260the limitation as if written in the body of this License. 261 262@item 263The Free Software Foundation may publish revised and/or new versions 264of the General Public License from time to time. Such new versions will 265be similar in spirit to the present version, but may differ in detail to 266address new problems or concerns. 267 268Each version is given a distinguishing version number. If the Program 269specifies a version number of this License which applies to it and ``any 270later version'', you have the option of following the terms and conditions 271either of that version or of any later version published by the Free 272Software Foundation. If the Program does not specify a version number of 273this License, you may choose any version ever published by the Free Software 274Foundation. 275 276@item 277If you wish to incorporate parts of the Program into other free 278programs whose distribution conditions are different, write to the author 279to ask for permission. For software which is copyrighted by the Free 280Software Foundation, write to the Free Software Foundation; we sometimes 281make exceptions for this. Our decision will be guided by the two goals 282of preserving the free status of all derivatives of our free software and 283of promoting the sharing and reuse of software generally. 284 285@iftex 286@heading NO WARRANTY 287@end iftex 288@ifinfo 289@center NO WARRANTY 290 291@end ifinfo 292 293@item 294BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY 295FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN 296OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES 297PROVIDE THE PROGRAM ``AS IS'' WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED 298OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 299MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS 300TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE 301PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, 302REPAIR OR CORRECTION. 303 304@item 305IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 306WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR 307REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, 308INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING 309OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED 310TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY 311YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER 312PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE 313POSSIBILITY OF SUCH DAMAGES. 314@end enumerate 315 316@iftex 317@heading END OF TERMS AND CONDITIONS 318@end iftex 319@ifinfo 320@center END OF TERMS AND CONDITIONS 321 322@end ifinfo 323 324@page 325@heading Appendix: How to Apply These Terms to Your New Programs 326 327 If you develop a new program, and you want it to be of the greatest 328possible use to the public, the best way to achieve this is to make it 329free software which everyone can redistribute and change under these terms. 330 331 To do so, attach the following notices to the program. It is safest 332to attach them to the start of each source file to most effectively 333convey the exclusion of warranty; and each file should have at least 334the ``copyright'' line and a pointer to where the full notice is found. 335 336@smallexample 337@var{one line to give the program's name and a brief idea of what it does.} 338Copyright (C) @var{yyyy} @var{name of author} 339 340This program is free software; you can redistribute it and/or modify 341it under the terms of the GNU General Public License as published by 342the Free Software Foundation; either version 2 of the License, or 343(at your option) any later version. 344 345This program is distributed in the hope that it will be useful, 346but WITHOUT ANY WARRANTY; without even the implied warranty of 347MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 348GNU General Public License for more details. 349 350You should have received a copy of the GNU General Public License 351along with this program; if not, write to the Free Software 352Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 353@end smallexample 354 355Also add information on how to contact you by electronic and paper mail. 356 357If the program is interactive, make it output a short notice like this 358when it starts in an interactive mode: 359 360@smallexample 361Gnomovision version 69, Copyright (C) @var{year} @var{name of author} 362Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 363This is free software, and you are welcome to redistribute it 364under certain conditions; type `show c' for details. 365@end smallexample 366 367The hypothetical commands @samp{show w} and @samp{show c} should show 368the appropriate parts of the General Public License. Of course, the 369commands you use may be called something other than @samp{show w} and 370@samp{show c}; they could even be mouse-clicks or menu items---whatever 371suits your program. 372 373You should also get your employer (if you work as a programmer) or your 374school, if any, to sign a ``copyright disclaimer'' for the program, if 375necessary. Here is a sample; alter the names: 376 377@example 378Yoyodyne, Inc., hereby disclaims all copyright interest in the program 379`Gnomovision' (which makes passes at compilers) written by James Hacker. 380 381@var{signature of Ty Coon}, 1 April 1989 382Ty Coon, President of Vice 383@end example 384 385This General Public License does not permit incorporating your program into 386proprietary programs. If your program is a subroutine library, you may 387consider it more useful to permit linking proprietary applications with the 388library. If this is what you want to do, use the GNU Lesser General 389Public License instead of this License. 390