gpl-2.0.texi (18223B)
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 8 Copyright @copyright{} 1989, 1991 Free Software Foundation, Inc. 9 <https://fsf.org/> 10 11 Everyone is permitted to copy and distribute verbatim copies 12 of 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 18 freedom to share and change it. By contrast, the GNU General Public 19 License is intended to guarantee your freedom to share and change free 20 software---to make sure the software is free for all its users. This 21 General Public License applies to most of the Free Software 22 Foundation's software and to any other program whose authors commit to 23 using it. (Some other Free Software Foundation software is covered by 24 the GNU Lesser General Public License instead.) You can apply it to 25 your programs, too. 26 27 When we speak of free software, we are referring to freedom, not 28 price. Our General Public Licenses are designed to make sure that you 29 have the freedom to distribute copies of free software (and charge for 30 this service if you wish), that you receive source code or can get it 31 if you want it, that you can change the software or use pieces of it 32 in 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 35 anyone to deny you these rights or to ask you to surrender the rights. 36 These restrictions translate to certain responsibilities for you if you 37 distribute copies of the software, or if you modify it. 38 39 For example, if you distribute copies of such a program, whether 40 gratis or for a fee, you must give the recipients all the rights that 41 you have. You must make sure that they, too, receive or can get the 42 source code. And you must show them these terms so they know their 43 rights. 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, 47 distribute and/or modify the software. 48 49 Also, for each author's protection and ours, we want to make certain 50 that everyone understands that there is no warranty for this free 51 software. If the software is modified by someone else and passed on, we 52 want its recipients to know that what they have is not the original, so 53 that any problems introduced by others will not reflect on the original 54 authors' reputations. 55 56 Finally, any free program is threatened constantly by software 57 patents. We wish to avoid the danger that redistributors of a free 58 program will individually obtain patent licenses, in effect making the 59 program proprietary. To prevent this, we have made it clear that any 60 patent must be licensed for everyone's free use or not licensed at all. 61 62 The precise terms and conditions for copying, distribution and 63 modification follow. 64 65 @heading TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 66 67 @enumerate 0 68 @item 69 This License applies to any program or other work which contains 70 a notice placed by the copyright holder saying it may be distributed 71 under the terms of this General Public License. The ``Program'', below, 72 refers to any such program or work, and a ``work based on the Program'' 73 means either the Program or any derivative work under copyright law: 74 that is to say, a work containing the Program or a portion of it, 75 either verbatim or with modifications and/or translated into another 76 language. (Hereinafter, translation is included without limitation in 77 the term ``modification''.) Each licensee is addressed as ``you''. 78 79 Activities other than copying, distribution and modification are not 80 covered by this License; they are outside its scope. The act of 81 running the Program is not restricted, and the output from the Program 82 is covered only if its contents constitute a work based on the 83 Program (independent of having been made by running the Program). 84 Whether that is true depends on what the Program does. 85 86 @item 87 You may copy and distribute verbatim copies of the Program's 88 source code as you receive it, in any medium, provided that you 89 conspicuously and appropriately publish on each copy an appropriate 90 copyright notice and disclaimer of warranty; keep intact all the 91 notices that refer to this License and to the absence of any warranty; 92 and give any other recipients of the Program a copy of this License 93 along with the Program. 94 95 You may charge a fee for the physical act of transferring a copy, and 96 you may at your option offer warranty protection in exchange for a fee. 97 98 @item 99 You may modify your copy or copies of the Program or any portion 100 of it, thus forming a work based on the Program, and copy and 101 distribute such modifications or work under the terms of Section 1 102 above, provided that you also meet all of these conditions: 103 104 @enumerate a 105 @item 106 You must cause the modified files to carry prominent notices 107 stating that you changed the files and the date of any change. 108 109 @item 110 You must cause any work that you distribute or publish, that in 111 whole or in part contains or is derived from the Program or any 112 part thereof, to be licensed as a whole at no charge to all third 113 parties under the terms of this License. 114 115 @item 116 If the modified program normally reads commands interactively 117 when run, you must cause it, when started running for such 118 interactive use in the most ordinary way, to print or display an 119 announcement including an appropriate copyright notice and a 120 notice that there is no warranty (or else, saying that you provide 121 a warranty) and that users may redistribute the program under 122 these conditions, and telling the user how to view a copy of this 123 License. (Exception: if the Program itself is interactive but 124 does not normally print such an announcement, your work based on 125 the Program is not required to print an announcement.) 126 @end enumerate 127 128 These requirements apply to the modified work as a whole. If 129 identifiable sections of that work are not derived from the Program, 130 and can be reasonably considered independent and separate works in 131 themselves, then this License, and its terms, do not apply to those 132 sections when you distribute them as separate works. But when you 133 distribute the same sections as part of a whole which is a work based 134 on the Program, the distribution of the whole must be on the terms of 135 this License, whose permissions for other licensees extend to the 136 entire whole, and thus to each and every part regardless of who wrote it. 137 138 Thus, it is not the intent of this section to claim rights or contest 139 your rights to work written entirely by you; rather, the intent is to 140 exercise the right to control the distribution of derivative or 141 collective works based on the Program. 142 143 In addition, mere aggregation of another work not based on the Program 144 with the Program (or with a work based on the Program) on a volume of 145 a storage or distribution medium does not bring the other work under 146 the scope of this License. 147 148 @item 149 You may copy and distribute the Program (or a work based on it, 150 under Section 2) in object code or executable form under the terms of 151 Sections 1 and 2 above provided that you also do one of the following: 152 153 @enumerate a 154 @item 155 Accompany it with the complete corresponding machine-readable 156 source code, which must be distributed under the terms of Sections 157 1 and 2 above on a medium customarily used for software interchange; or, 158 159 @item 160 Accompany it with a written offer, valid for at least three 161 years, to give any third party, for a charge no more than your 162 cost of physically performing source distribution, a complete 163 machine-readable copy of the corresponding source code, to be 164 distributed under the terms of Sections 1 and 2 above on a medium 165 customarily used for software interchange; or, 166 167 @item 168 Accompany it with the information you received as to the offer 169 to distribute corresponding source code. (This alternative is 170 allowed only for noncommercial distribution and only if you 171 received the program in object code or executable form with such 172 an offer, in accord with Subsection b above.) 173 @end enumerate 174 175 The source code for a work means the preferred form of the work for 176 making modifications to it. For an executable work, complete source 177 code means all the source code for all modules it contains, plus any 178 associated interface definition files, plus the scripts used to 179 control compilation and installation of the executable. However, as a 180 special exception, the source code distributed need not include 181 anything that is normally distributed (in either source or binary 182 form) with the major components (compiler, kernel, and so on) of the 183 operating system on which the executable runs, unless that component 184 itself accompanies the executable. 185 186 If distribution of executable or object code is made by offering 187 access to copy from a designated place, then offering equivalent 188 access to copy the source code from the same place counts as 189 distribution of the source code, even though third parties are not 190 compelled to copy the source along with the object code. 191 192 @item 193 You may not copy, modify, sublicense, or distribute the Program 194 except as expressly provided under this License. Any attempt 195 otherwise to copy, modify, sublicense or distribute the Program is 196 void, and will automatically terminate your rights under this License. 197 However, parties who have received copies, or rights, from you under 198 this License will not have their licenses terminated so long as such 199 parties remain in full compliance. 200 201 @item 202 You are not required to accept this License, since you have not 203 signed it. However, nothing else grants you permission to modify or 204 distribute the Program or its derivative works. These actions are 205 prohibited by law if you do not accept this License. Therefore, by 206 modifying or distributing the Program (or any work based on the 207 Program), you indicate your acceptance of this License to do so, and 208 all its terms and conditions for copying, distributing or modifying 209 the Program or works based on it. 210 211 @item 212 Each time you redistribute the Program (or any work based on the 213 Program), the recipient automatically receives a license from the 214 original licensor to copy, distribute or modify the Program subject to 215 these terms and conditions. You may not impose any further 216 restrictions on the recipients' exercise of the rights granted herein. 217 You are not responsible for enforcing compliance by third parties to 218 this License. 219 220 @item 221 If, as a consequence of a court judgment or allegation of patent 222 infringement or for any other reason (not limited to patent issues), 223 conditions are imposed on you (whether by court order, agreement or 224 otherwise) that contradict the conditions of this License, they do not 225 excuse you from the conditions of this License. If you cannot 226 distribute so as to satisfy simultaneously your obligations under this 227 License and any other pertinent obligations, then as a consequence you 228 may not distribute the Program at all. For example, if a patent 229 license would not permit royalty-free redistribution of the Program by 230 all those who receive copies directly or indirectly through you, then 231 the only way you could satisfy both it and this License would be to 232 refrain entirely from distribution of the Program. 233 234 If any portion of this section is held invalid or unenforceable under 235 any particular circumstance, the balance of the section is intended to 236 apply and the section as a whole is intended to apply in other 237 circumstances. 238 239 It is not the purpose of this section to induce you to infringe any 240 patents or other property right claims or to contest validity of any 241 such claims; this section has the sole purpose of protecting the 242 integrity of the free software distribution system, which is 243 implemented by public license practices. Many people have made 244 generous contributions to the wide range of software distributed 245 through that system in reliance on consistent application of that 246 system; it is up to the author/donor to decide if he or she is willing 247 to distribute software through any other system and a licensee cannot 248 impose that choice. 249 250 This section is intended to make thoroughly clear what is believed to 251 be a consequence of the rest of this License. 252 253 @item 254 If the distribution and/or use of the Program is restricted in 255 certain countries either by patents or by copyrighted interfaces, the 256 original copyright holder who places the Program under this License 257 may add an explicit geographical distribution limitation excluding 258 those countries, so that distribution is permitted only in or among 259 countries not thus excluded. In such case, this License incorporates 260 the limitation as if written in the body of this License. 261 262 @item 263 The Free Software Foundation may publish revised and/or new versions 264 of the General Public License from time to time. Such new versions will 265 be similar in spirit to the present version, but may differ in detail to 266 address new problems or concerns. 267 268 Each version is given a distinguishing version number. If the Program 269 specifies a version number of this License which applies to it and ``any 270 later version'', you have the option of following the terms and conditions 271 either of that version or of any later version published by the Free 272 Software Foundation. If the Program does not specify a version number of 273 this License, you may choose any version ever published by the Free Software 274 Foundation. 275 276 @item 277 If you wish to incorporate parts of the Program into other free 278 programs whose distribution conditions are different, write to the author 279 to ask for permission. For software which is copyrighted by the Free 280 Software Foundation, write to the Free Software Foundation; we sometimes 281 make exceptions for this. Our decision will be guided by the two goals 282 of preserving the free status of all derivatives of our free software and 283 of 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 294 BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY 295 FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW@. EXCEPT WHEN 296 OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES 297 PROVIDE THE PROGRAM ``AS IS'' WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED 298 OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 299 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE@. THE ENTIRE RISK AS 300 TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU@. SHOULD THE 301 PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, 302 REPAIR OR CORRECTION. 303 304 @item 305 IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 306 WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR 307 REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, 308 INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING 309 OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED 310 TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY 311 YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER 312 PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE 313 POSSIBILITY 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 328 possible use to the public, the best way to achieve this is to make it 329 free 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 332 to attach them to the start of each source file to most effectively 333 convey the exclusion of warranty; and each file should have at least 334 the ``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.} 338 Copyright (C) @var{yyyy} @var{name of author} 339 340 This program is free software; you can redistribute it and/or modify 341 it under the terms of the GNU General Public License as published by 342 the Free Software Foundation; either version 2 of the License, or 343 (at your option) any later version. 344 345 This program is distributed in the hope that it will be useful, 346 but WITHOUT ANY WARRANTY; without even the implied warranty of 347 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE@. See the 348 GNU General Public License for more details. 349 350 You should have received a copy of the GNU General Public License 351 along with this program; if not, see <https://www.gnu.org/licenses/>. 352 @end smallexample 353 354 Also add information on how to contact you by electronic and paper mail. 355 356 If the program is interactive, make it output a short notice like this 357 when it starts in an interactive mode: 358 359 @smallexample 360 Gnomovision version 69, Copyright (C) @var{year} @var{name of author} 361 Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 362 This is free software, and you are welcome to redistribute it 363 under certain conditions; type `show c' for details. 364 @end smallexample 365 366 The hypothetical commands @samp{show w} and @samp{show c} should show 367 the appropriate parts of the General Public License. Of course, the 368 commands you use may be called something other than @samp{show w} and 369 @samp{show c}; they could even be mouse-clicks or menu items---whatever 370 suits your program. 371 372 You should also get your employer (if you work as a programmer) or your 373 school, if any, to sign a ``copyright disclaimer'' for the program, if 374 necessary. Here is a sample; alter the names: 375 376 @example 377 Yoyodyne, Inc., hereby disclaims all copyright interest in the program 378 `Gnomovision' (which makes passes at compilers) written by James Hacker. 379 380 @var{signature of Moe Ghoul}, 1 April 1989 381 Moe Ghoul, President of Vice 382 @end example 383 384 This General Public License does not permit incorporating your program into 385 proprietary programs. If your program is a subroutine library, you may 386 consider it more useful to permit linking proprietary applications with the 387 library. If this is what you want to do, use the GNU Lesser General 388 Public License instead of this License.