gpl.texi (18339B)
1 @node Copying 2 @appendix GNU GENERAL PUBLIC LICENSE 3 4 @cindex GPL, GNU General Public License 5 @center Version 2, June 1991 6 7 @display 8 Copyright @copyright{} 1989, 1991 Free Software Foundation, Inc. 9 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 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 @appendixsubsec 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 Library 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 @iftex 66 @appendixsubsec TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 67 @end iftex 68 @ifinfo 69 @center TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 70 @end ifinfo 71 72 @enumerate 73 @item 74 This License applies to any program or other work which contains 75 a notice placed by the copyright holder saying it may be distributed 76 under the terms of this General Public License. The ``Program'', below, 77 refers to any such program or work, and a ``work based on the Program'' 78 means either the Program or any derivative work under copyright law: 79 that is to say, a work containing the Program or a portion of it, 80 either verbatim or with modifications and/or translated into another 81 language. (Hereinafter, translation is included without limitation in 82 the term ``modification''.) Each licensee is addressed as ``you''. 83 84 Activities other than copying, distribution and modification are not 85 covered by this License; they are outside its scope. The act of 86 running the Program is not restricted, and the output from the Program 87 is covered only if its contents constitute a work based on the 88 Program (independent of having been made by running the Program). 89 Whether that is true depends on what the Program does. 90 91 @item 92 You may copy and distribute verbatim copies of the Program's 93 source code as you receive it, in any medium, provided that you 94 conspicuously and appropriately publish on each copy an appropriate 95 copyright notice and disclaimer of warranty; keep intact all the 96 notices that refer to this License and to the absence of any warranty; 97 and give any other recipients of the Program a copy of this License 98 along with the Program. 99 100 You may charge a fee for the physical act of transferring a copy, and 101 you may at your option offer warranty protection in exchange for a fee. 102 103 @item 104 You may modify your copy or copies of the Program or any portion 105 of it, thus forming a work based on the Program, and copy and 106 distribute such modifications or work under the terms of Section 1 107 above, provided that you also meet all of these conditions: 108 109 @enumerate a 110 @item 111 You must cause the modified files to carry prominent notices 112 stating that you changed the files and the date of any change. 113 114 @item 115 You must cause any work that you distribute or publish, that in 116 whole or in part contains or is derived from the Program or any 117 part thereof, to be licensed as a whole at no charge to all third 118 parties under the terms of this License. 119 120 @item 121 If the modified program normally reads commands interactively 122 when run, you must cause it, when started running for such 123 interactive use in the most ordinary way, to print or display an 124 announcement including an appropriate copyright notice and a 125 notice that there is no warranty (or else, saying that you provide 126 a warranty) and that users may redistribute the program under 127 these conditions, and telling the user how to view a copy of this 128 License. (Exception: if the Program itself is interactive but 129 does not normally print such an announcement, your work based on 130 the Program is not required to print an announcement.) 131 @end enumerate 132 133 These requirements apply to the modified work as a whole. If 134 identifiable sections of that work are not derived from the Program, 135 and can be reasonably considered independent and separate works in 136 themselves, then this License, and its terms, do not apply to those 137 sections when you distribute them as separate works. But when you 138 distribute the same sections as part of a whole which is a work based 139 on the Program, the distribution of the whole must be on the terms of 140 this License, whose permissions for other licensees extend to the 141 entire whole, and thus to each and every part regardless of who wrote it. 142 143 Thus, it is not the intent of this section to claim rights or contest 144 your rights to work written entirely by you; rather, the intent is to 145 exercise the right to control the distribution of derivative or 146 collective works based on the Program. 147 148 In addition, mere aggregation of another work not based on the Program 149 with the Program (or with a work based on the Program) on a volume of 150 a storage or distribution medium does not bring the other work under 151 the scope of this License. 152 153 @item 154 You may copy and distribute the Program (or a work based on it, 155 under Section 2) in object code or executable form under the terms of 156 Sections 1 and 2 above provided that you also do one of the following: 157 158 @enumerate a 159 @item 160 Accompany it with the complete corresponding machine-readable 161 source code, which must be distributed under the terms of Sections 162 1 and 2 above on a medium customarily used for software interchange; or, 163 164 @item 165 Accompany it with a written offer, valid for at least three 166 years, to give any third party, for a charge no more than your 167 cost of physically performing source distribution, a complete 168 machine-readable copy of the corresponding source code, to be 169 distributed under the terms of Sections 1 and 2 above on a medium 170 customarily used for software interchange; or, 171 172 @item 173 Accompany it with the information you received as to the offer 174 to distribute corresponding source code. (This alternative is 175 allowed only for noncommercial distribution and only if you 176 received the program in object code or executable form with such 177 an offer, in accord with Subsection b above.) 178 @end enumerate 179 180 The source code for a work means the preferred form of the work for 181 making modifications to it. For an executable work, complete source 182 code means all the source code for all modules it contains, plus any 183 associated interface definition files, plus the scripts used to 184 control compilation and installation of the executable. However, as a 185 special exception, the source code distributed need not include 186 anything that is normally distributed (in either source or binary 187 form) with the major components (compiler, kernel, and so on) of the 188 operating system on which the executable runs, unless that component 189 itself accompanies the executable. 190 191 If distribution of executable or object code is made by offering 192 access to copy from a designated place, then offering equivalent 193 access to copy the source code from the same place counts as 194 distribution of the source code, even though third parties are not 195 compelled to copy the source along with the object code. 196 197 @item 198 You may not copy, modify, sublicense, or distribute the Program 199 except as expressly provided under this License. Any attempt 200 otherwise to copy, modify, sublicense or distribute the Program is 201 void, and will automatically terminate your rights under this License. 202 However, parties who have received copies, or rights, from you under 203 this License will not have their licenses terminated so long as such 204 parties remain in full compliance. 205 206 @item 207 You are not required to accept this License, since you have not 208 signed it. However, nothing else grants you permission to modify or 209 distribute the Program or its derivative works. These actions are 210 prohibited by law if you do not accept this License. Therefore, by 211 modifying or distributing the Program (or any work based on the 212 Program), you indicate your acceptance of this License to do so, and 213 all its terms and conditions for copying, distributing or modifying 214 the Program or works based on it. 215 216 @item 217 Each time you redistribute the Program (or any work based on the 218 Program), the recipient automatically receives a license from the 219 original licensor to copy, distribute or modify the Program subject to 220 these terms and conditions. You may not impose any further 221 restrictions on the recipients' exercise of the rights granted herein. 222 You are not responsible for enforcing compliance by third parties to 223 this License. 224 225 @item 226 If, as a consequence of a court judgment or allegation of patent 227 infringement or for any other reason (not limited to patent issues), 228 conditions are imposed on you (whether by court order, agreement or 229 otherwise) that contradict the conditions of this License, they do not 230 excuse you from the conditions of this License. If you cannot 231 distribute so as to satisfy simultaneously your obligations under this 232 License and any other pertinent obligations, then as a consequence you 233 may not distribute the Program at all. For example, if a patent 234 license would not permit royalty-free redistribution of the Program by 235 all those who receive copies directly or indirectly through you, then 236 the only way you could satisfy both it and this License would be to 237 refrain entirely from distribution of the Program. 238 239 If any portion of this section is held invalid or unenforceable under 240 any particular circumstance, the balance of the section is intended to 241 apply and the section as a whole is intended to apply in other 242 circumstances. 243 244 It is not the purpose of this section to induce you to infringe any 245 patents or other property right claims or to contest validity of any 246 such claims; this section has the sole purpose of protecting the 247 integrity of the free software distribution system, which is 248 implemented by public license practices. Many people have made 249 generous contributions to the wide range of software distributed 250 through that system in reliance on consistent application of that 251 system; it is up to the author/donor to decide if he or she is willing 252 to distribute software through any other system and a licensee cannot 253 impose that choice. 254 255 This section is intended to make thoroughly clear what is believed to 256 be a consequence of the rest of this License. 257 258 @item 259 If the distribution and/or use of the Program is restricted in 260 certain countries either by patents or by copyrighted interfaces, the 261 original copyright holder who places the Program under this License 262 may add an explicit geographical distribution limitation excluding 263 those countries, so that distribution is permitted only in or among 264 countries not thus excluded. In such case, this License incorporates 265 the limitation as if written in the body of this License. 266 267 @item 268 The Free Software Foundation may publish revised and/or new versions 269 of the General Public License from time to time. Such new versions will 270 be similar in spirit to the present version, but may differ in detail to 271 address new problems or concerns. 272 273 Each version is given a distinguishing version number. If the Program 274 specifies a version number of this License which applies to it and ``any 275 later version'', you have the option of following the terms and conditions 276 either of that version or of any later version published by the Free 277 Software Foundation. If the Program does not specify a version number of 278 this License, you may choose any version ever published by the Free Software 279 Foundation. 280 281 @item 282 If you wish to incorporate parts of the Program into other free 283 programs whose distribution conditions are different, write to the author 284 to ask for permission. For software which is copyrighted by the Free 285 Software Foundation, write to the Free Software Foundation; we sometimes 286 make exceptions for this. Our decision will be guided by the two goals 287 of preserving the free status of all derivatives of our free software and 288 of promoting the sharing and reuse of software generally. 289 290 @item 291 BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY 292 FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN 293 OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES 294 PROVIDE THE PROGRAM ``AS IS'' WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED 295 OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 296 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS 297 TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE 298 PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, 299 REPAIR OR CORRECTION. 300 301 @item 302 IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 303 WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR 304 REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, 305 INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING 306 OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED 307 TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY 308 YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER 309 PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE 310 POSSIBILITY OF SUCH DAMAGES. 311 @end enumerate 312 313 @iftex 314 @heading END OF TERMS AND CONDITIONS 315 @end iftex 316 @ifinfo 317 @center END OF TERMS AND CONDITIONS 318 @end ifinfo 319 320 @page 321 @unnumberedsec How to Apply These Terms to Your New Programs 322 323 If you develop a new program, and you want it to be of the greatest 324 possible use to the public, the best way to achieve this is to make it 325 free software which everyone can redistribute and change under these terms. 326 327 To do so, attach the following notices to the program. It is safest 328 to attach them to the start of each source file to most effectively 329 convey the exclusion of warranty; and each file should have at least 330 the ``copyright'' line and a pointer to where the full notice is found. 331 332 @smallexample 333 @var{one line to give the program's name and an idea of what it does.} 334 Copyright (C) 19@var{yy} @var{name of author} 335 336 This program is free software; you can redistribute it and/or 337 modify it under the terms of the GNU General Public License 338 as published by the Free Software Foundation; either version 2 339 of the License, or (at your option) any later version. 340 341 This program is distributed in the hope that it will be useful, 342 but WITHOUT ANY WARRANTY; without even the implied warranty of 343 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 344 GNU General Public License for more details. 345 346 You should have received a copy of the GNU General Public License along 347 with this program; if not, write to the Free Software Foundation, Inc., 348 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 349 @end smallexample 350 351 Also add information on how to contact you by electronic and paper mail. 352 353 If the program is interactive, make it output a short notice like this 354 when it starts in an interactive mode: 355 356 @smallexample 357 Gnomovision version 69, Copyright (C) 19@var{yy} @var{name of author} 358 Gnomovision comes with ABSOLUTELY NO WARRANTY; for details 359 type `show w'. This is free software, and you are welcome 360 to redistribute it under certain conditions; type `show c' 361 for details. 362 @end smallexample 363 364 The hypothetical commands @samp{show w} and @samp{show c} should show 365 the appropriate parts of the General Public License. Of course, the 366 commands you use may be called something other than @samp{show w} and 367 @samp{show c}; they could even be mouse-clicks or menu items---whatever 368 suits your program. 369 370 You should also get your employer (if you work as a programmer) or your 371 school, if any, to sign a ``copyright disclaimer'' for the program, if 372 necessary. Here is a sample; alter the names: 373 374 @smallexample 375 @group 376 Yoyodyne, Inc., hereby disclaims all copyright 377 interest in the program `Gnomovision' 378 (which makes passes at compilers) written 379 by James Hacker. 380 381 @var{signature of Ty Coon}, 1 April 1989 382 Ty Coon, President of Vice 383 @end group 384 @end smallexample 385 386 This General Public License does not permit incorporating your program into 387 proprietary programs. If your program is a subroutine library, you may 388 consider it more useful to permit linking proprietary applications with the 389 library. If this is what you want to do, use the GNU Library General 390 Public License instead of this License.