1 2 GNU LESSER GENERAL PUBLIC LICENSE 3 Version 2.1, February 1999 4 5 Copyright (C) 1991, 1999 Free Software Foundation, Inc. 6 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 7 Everyone is permitted to copy and distribute verbatim copies 8 of this license document, but changing it is not allowed. 9 10[This is the first released version of the Lesser GPL. It also counts 11 as the successor of the GNU Library Public License, version 2, hence 12 the version number 2.1.] 13 14 Preamble 15 16 The licenses for most software are designed to take away your 17freedom to share and change it. By contrast, the GNU General Public 18Licenses are intended to guarantee your freedom to share and change 19free software--to make sure the software is free for all its users. 20 21 This license, the Lesser General Public License, applies to some 22specially designated software packages--typically libraries--of the 23Free Software Foundation and other authors who decide to use it. You 24can use it too, but we suggest you first think carefully about whether 25this license or the ordinary General Public License is the better 26strategy to use in any particular case, based on the explanations 27below. 28 29 When we speak of free software, we are referring to freedom of use, 30not price. Our General Public Licenses are designed to make sure that 31you have the freedom to distribute copies of free software (and charge 32for this service if you wish); that you receive source code or can get 33it if you want it; that you can change the software and use pieces of 34it in new free programs; and that you are informed that you can do 35these things. 36 37 To protect your rights, we need to make restrictions that forbid 38distributors to deny you these rights or to ask you to surrender these 39rights. These restrictions translate to certain responsibilities for 40you if you distribute copies of the library or if you modify it. 41 42 For example, if you distribute copies of the library, whether gratis 43or for a fee, you must give the recipients all the rights that we gave 44you. You must make sure that they, too, receive or can get the source 45code. If you link other code with the library, you must provide 46complete object files to the recipients, so that they can relink them 47with the library after making changes to the library and recompiling 48it. And you must show them these terms so they know their rights. 49 50 We protect your rights with a two-step method: (1) we copyright the 51library, and (2) we offer you this license, which gives you legal 52permission to copy, distribute and/or modify the library. 53 54 To protect each distributor, we want to make it very clear that 55there is no warranty for the free library. Also, if the library is 56modified by someone else and passed on, the recipients should know 57that what they have is not the original version, so that the original 58author's reputation will not be affected by problems that might be 59introduced by others. 60 61 Finally, software patents pose a constant threat to the existence of 62any free program. We wish to make sure that a company cannot 63effectively restrict the users of a free program by obtaining a 64restrictive license from a patent holder. Therefore, we insist that 65any patent license obtained for a version of the library must be 66consistent with the full freedom of use specified in this license. 67 68 Most GNU software, including some libraries, is covered by the 69ordinary GNU General Public License. This license, the GNU Lesser 70General Public License, applies to certain designated libraries, and 71is quite different from the ordinary General Public License. We use 72this license for certain libraries in order to permit linking those 73libraries into non-free programs. 74 75 When a program is linked with a library, whether statically or using 76a shared library, the combination of the two is legally speaking a 77combined work, a derivative of the original library. The ordinary 78General Public License therefore permits such linking only if the 79entire combination fits its criteria of freedom. The Lesser General 80Public License permits more lax criteria for linking other code with 81the library. 82 83 We call this license the "Lesser" General Public License because it 84does Less to protect the user's freedom than the ordinary General 85Public License. It also provides other free software developers Less 86of an advantage over competing non-free programs. These disadvantages 87are the reason we use the ordinary General Public License for many 88libraries. However, the Lesser license provides advantages in certain 89special circumstances. 90 91 For example, on rare occasions, there may be a special need to 92encourage the widest possible use of a certain library, so that it 93becomes a de-facto standard. To achieve this, non-free programs must 94be allowed to use the library. A more frequent case is that a free 95library does the same job as widely used non-free libraries. In this 96case, there is little to gain by limiting the free library to free 97software only, so we use the Lesser General Public License. 98 99 In other cases, permission to use a particular library in non-free 100programs enables a greater number of people to use a large body of 101free software. For example, permission to use the GNU C Library in 102non-free programs enables many more people to use the whole GNU 103operating system, as well as its variant, the GNU/Linux operating 104system. 105 106 Although the Lesser General Public License is Less protective of the 107users' freedom, it does ensure that the user of a program that is 108linked with the Library has the freedom and the wherewithal to run 109that program using a modified version of the Library. 110 111 The precise terms and conditions for copying, distribution and 112modification follow. Pay close attention to the difference between a 113"work based on the library" and a "work that uses the library". The 114former contains code derived from the library, whereas the latter must 115be combined with the library in order to run. 116 117 GNU LESSER GENERAL PUBLIC LICENSE 118 TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 119 120 0. This License Agreement applies to any software library or other 121program which contains a notice placed by the copyright holder or 122other authorized party saying it may be distributed under the terms of 123this Lesser General Public License (also called "this License"). 124Each licensee is addressed as "you". 125 126 A "library" means a collection of software functions and/or data 127prepared so as to be conveniently linked with application programs 128(which use some of those functions and data) to form executables. 129 130 The "Library", below, refers to any such software library or work 131which has been distributed under these terms. A "work based on the 132Library" means either the Library or any derivative work under 133copyright law: that is to say, a work containing the Library or a 134portion of it, either verbatim or with modifications and/or translated 135straightforwardly into another language. (Hereinafter, translation is 136included without limitation in the term "modification".) 137 138 "Source code" for a work means the preferred form of the work for 139making modifications to it. For a library, complete source code means 140all the source code for all modules it contains, plus any associated 141interface definition files, plus the scripts used to control 142compilation and installation of the library. 143 144 Activities other than copying, distribution and modification are not 145covered by this License; they are outside its scope. The act of 146running a program using the Library is not restricted, and output from 147such a program is covered only if its contents constitute a work based 148on the Library (independent of the use of the Library in a tool for 149writing it). Whether that is true depends on what the Library does 150and what the program that uses the Library does. 151 152 1. You may copy and distribute verbatim copies of the Library's 153complete source code as you receive it, in any medium, provided that 154you conspicuously and appropriately publish on each copy an 155appropriate copyright notice and disclaimer of warranty; keep intact 156all the notices that refer to this License and to the absence of any 157warranty; and distribute a copy of this License along with the 158Library. 159 160 You may charge a fee for the physical act of transferring a copy, 161and you may at your option offer warranty protection in exchange for a 162fee. 163 164 2. You may modify your copy or copies of the Library or any portion 165of it, thus forming a work based on the Library, and copy and 166distribute such modifications or work under the terms of Section 1 167above, provided that you also meet all of these conditions: 168 169 a) The modified work must itself be a software library. 170 171 b) You must cause the files modified to carry prominent notices 172 stating that you changed the files and the date of any change. 173 174 c) You must cause the whole of the work to be licensed at no 175 charge to all third parties under the terms of this License. 176 177 d) If a facility in the modified Library refers to a function or a 178 table of data to be supplied by an application program that uses 179 the facility, other than as an argument passed when the facility 180 is invoked, then you must make a good faith effort to ensure that, 181 in the event an application does not supply such function or 182 table, the facility still operates, and performs whatever part of 183 its purpose remains meaningful. 184 185 (For example, a function in a library to compute square roots has 186 a purpose that is entirely well-defined independent of the 187 application. Therefore, Subsection 2d requires that any 188 application-supplied function or table used by this function must 189 be optional: if the application does not supply it, the square 190 root function must still compute square roots.) 191 192These requirements apply to the modified work as a whole. If 193identifiable sections of that work are not derived from the Library, 194and can be reasonably considered independent and separate works in 195themselves, then this License, and its terms, do not apply to those 196sections when you distribute them as separate works. But when you 197distribute the same sections as part of a whole which is a work based 198on the Library, the distribution of the whole must be on the terms of 199this License, whose permissions for other licensees extend to the 200entire whole, and thus to each and every part regardless of who wrote 201it. 202 203Thus, it is not the intent of this section to claim rights or contest 204your rights to work written entirely by you; rather, the intent is to 205exercise the right to control the distribution of derivative or 206collective works based on the Library. 207 208In addition, mere aggregation of another work not based on the Library 209with the Library (or with a work based on the Library) on a volume of 210a storage or distribution medium does not bring the other work under 211the scope of this License. 212 213 3. You may opt to apply the terms of the ordinary GNU General Public 214License instead of this License to a given copy of the Library. To do 215this, you must alter all the notices that refer to this License, so 216that they refer to the ordinary GNU General Public License, version 2, 217instead of to this License. (If a newer version than version 2 of the 218ordinary GNU General Public License has appeared, then you can specify 219that version instead if you wish.) Do not make any other change in 220these notices. 221 222 Once this change is made in a given copy, it is irreversible for 223that copy, so the ordinary GNU General Public License applies to all 224subsequent copies and derivative works made from that copy. 225 226 This option is useful when you wish to copy part of the code of 227the Library into a program that is not a library. 228 229 4. You may copy and distribute the Library (or a portion or 230derivative of it, under Section 2) in object code or executable form 231under the terms of Sections 1 and 2 above provided that you accompany 232it with the complete corresponding machine-readable source code, which 233must be distributed under the terms of Sections 1 and 2 above on a 234medium customarily used for software interchange. 235 236 If distribution of object code is made by offering access to copy 237from a designated place, then offering equivalent access to copy the 238source code from the same place satisfies the requirement to 239distribute the source code, even though third parties are not 240compelled to copy the source along with the object code. 241 242 5. A program that contains no derivative of any portion of the 243Library, but is designed to work with the Library by being compiled or 244linked with it, is called a "work that uses the Library". Such a 245work, in isolation, is not a derivative work of the Library, and 246therefore falls outside the scope of this License. 247 248 However, linking a "work that uses the Library" with the Library 249creates an executable that is a derivative of the Library (because it 250contains portions of the Library), rather than a "work that uses the 251library". The executable is therefore covered by this License. 252Section 6 states terms for distribution of such executables. 253 254 When a "work that uses the Library" uses material from a header file 255that is part of the Library, the object code for the work may be a 256derivative work of the Library even though the source code is not. 257Whether this is true is especially significant if the work can be 258linked without the Library, or if the work is itself a library. The 259threshold for this to be true is not precisely defined by law. 260 261 If such an object file uses only numerical parameters, data 262structure layouts and accessors, and small macros and small inline 263functions (ten lines or less in length), then the use of the object 264file is unrestricted, regardless of whether it is legally a derivative 265work. (Executables containing this object code plus portions of the 266Library will still fall under Section 6.) 267 268 Otherwise, if the work is a derivative of the Library, you may 269distribute the object code for the work under the terms of Section 6. 270Any executables containing that work also fall under Section 6, 271whether or not they are linked directly with the Library itself. 272 273 6. As an exception to the Sections above, you may also combine or 274link a "work that uses the Library" with the Library to produce a 275work containing portions of the Library, and distribute that work 276under terms of your choice, provided that the terms permit 277modification of the work for the customer's own use and reverse 278engineering for debugging such modifications. 279 280 You must give prominent notice with each copy of the work that the 281Library is used in it and that the Library and its use are covered by 282this License. You must supply a copy of this License. If the work 283during execution displays copyright notices, you must include the 284copyright notice for the Library among them, as well as a reference 285directing the user to the copy of this License. Also, you must do one 286of these things: 287 288 a) Accompany the work with the complete corresponding 289 machine-readable source code for the Library including whatever 290 changes were used in the work (which must be distributed under 291 Sections 1 and 2 above); and, if the work is an executable linked 292 with the Library, with the complete machine-readable "work that 293 uses the Library", as object code and/or source code, so that the 294 user can modify the Library and then relink to produce a modified 295 executable containing the modified Library. (It is understood 296 that the user who changes the contents of definitions files in the 297 Library will not necessarily be able to recompile the application 298 to use the modified definitions.) 299 300 b) Use a suitable shared library mechanism for linking with the 301 Library. A suitable mechanism is one that (1) uses at run time a 302 copy of the library already present on the user's computer system, 303 rather than copying library functions into the executable, and (2) 304 will operate properly with a modified version of the library, if 305 the user installs one, as long as the modified version is 306 interface-compatible with the version that the work was made with. 307 308 c) Accompany the work with a written offer, valid for at least 309 three years, to give the same user the materials specified in 310 Subsection 6a, above, for a charge no more than the cost of 311 performing this distribution. 312 313 d) If distribution of the work is made by offering access to copy 314 from a designated place, offer equivalent access to copy the above 315 specified materials from the same place. 316 317 e) Verify that the user has already received a copy of these 318 materials or that you have already sent this user a copy. 319 320 For an executable, the required form of the "work that uses the 321Library" must include any data and utility programs needed for 322reproducing the executable from it. However, as a special exception, 323the materials to be distributed need not include anything that is 324normally distributed (in either source or binary form) with the major 325components (compiler, kernel, and so on) of the operating system on 326which the executable runs, unless that component itself accompanies 327the executable. 328 329 It may happen that this requirement contradicts the license 330restrictions of other proprietary libraries that do not normally 331accompany the operating system. Such a contradiction means you cannot 332use both them and the Library together in an executable that you 333distribute. 334 335 7. You may place library facilities that are a work based on the 336Library side-by-side in a single library together with other library 337facilities not covered by this License, and distribute such a combined 338library, provided that the separate distribution of the work based on 339the Library and of the other library facilities is otherwise 340permitted, and provided that you do these two things: 341 342 a) Accompany the combined library with a copy of the same work 343 based on the Library, uncombined with any other library 344 facilities. This must be distributed under the terms of the 345 Sections above. 346 347 b) Give prominent notice with the combined library of the fact 348 that part of it is a work based on the Library, and explaining 349 where to find the accompanying uncombined form of the same work. 350 351 8. You may not copy, modify, sublicense, link with, or distribute 352the Library except as expressly provided under this License. Any 353attempt otherwise to copy, modify, sublicense, link with, or 354distribute the Library is void, and will automatically terminate your 355rights under this License. However, parties who have received copies, 356or rights, from you under this License will not have their licenses 357terminated so long as such parties remain in full compliance. 358 359 9. You are not required to accept this License, since you have not 360signed it. However, nothing else grants you permission to modify or 361distribute the Library or its derivative works. These actions are 362prohibited by law if you do not accept this License. Therefore, by 363modifying or distributing the Library (or any work based on the 364Library), you indicate your acceptance of this License to do so, and 365all its terms and conditions for copying, distributing or modifying 366the Library or works based on it. 367 368 10. Each time you redistribute the Library (or any work based on the 369Library), the recipient automatically receives a license from the 370original licensor to copy, distribute, link with or modify the Library 371subject to these terms and conditions. You may not impose any further 372restrictions on the recipients' exercise of the rights granted herein. 373You are not responsible for enforcing compliance by third parties with 374this License. 375 376 11. If, as a consequence of a court judgment or allegation of patent 377infringement or for any other reason (not limited to patent issues), 378conditions are imposed on you (whether by court order, agreement or 379otherwise) that contradict the conditions of this License, they do not 380excuse you from the conditions of this License. If you cannot 381distribute so as to satisfy simultaneously your obligations under this 382License and any other pertinent obligations, then as a consequence you 383may not distribute the Library at all. For example, if a patent 384license would not permit royalty-free redistribution of the Library by 385all those who receive copies directly or indirectly through you, then 386the only way you could satisfy both it and this License would be to 387refrain entirely from distribution of the Library. 388 389If any portion of this section is held invalid or unenforceable under 390any particular circumstance, the balance of the section is intended to 391apply, and the section as a whole is intended to apply in other 392circumstances. 393 394It is not the purpose of this section to induce you to infringe any 395patents or other property right claims or to contest validity of any 396such claims; this section has the sole purpose of protecting the 397integrity of the free software distribution system which is 398implemented by public license practices. Many people have made 399generous contributions to the wide range of software distributed 400through that system in reliance on consistent application of that 401system; it is up to the author/donor to decide if he or she is willing 402to distribute software through any other system and a licensee cannot 403impose that choice. 404 405This section is intended to make thoroughly clear what is believed to 406be a consequence of the rest of this License. 407 408 12. If the distribution and/or use of the Library is restricted in 409certain countries either by patents or by copyrighted interfaces, the 410original copyright holder who places the Library under this License 411may add an explicit geographical distribution limitation excluding those 412countries, so that distribution is permitted only in or among 413countries not thus excluded. In such case, this License incorporates 414the limitation as if written in the body of this License. 415 416 13. The Free Software Foundation may publish revised and/or new 417versions of the Lesser General Public License from time to time. 418Such new versions will be similar in spirit to the present version, 419but may differ in detail to address new problems or concerns. 420 421Each version is given a distinguishing version number. If the Library 422specifies a version number of this License which applies to it and 423"any later version", you have the option of following the terms and 424conditions either of that version or of any later version published by 425the Free Software Foundation. If the Library does not specify a 426license version number, you may choose any version ever published by 427the Free Software Foundation. 428 429 14. If you wish to incorporate parts of the Library into other free 430programs whose distribution conditions are incompatible with these, 431write to the author to ask for permission. For software which is 432copyrighted by the Free Software Foundation, write to the Free 433Software Foundation; we sometimes make exceptions for this. Our 434decision will be guided by the two goals of preserving the free status 435of all derivatives of our free software and of promoting the sharing 436and reuse of software generally. 437 438 NO WARRANTY 439 440 15. BECAUSE THE LIBRARY IS LICENSED FREE OF CHARGE, THERE IS NO 441WARRANTY FOR THE LIBRARY, TO THE EXTENT PERMITTED BY APPLICABLE LAW. 442EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR 443OTHER PARTIES PROVIDE THE LIBRARY "AS IS" WITHOUT WARRANTY OF ANY 444KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE 445IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 446PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE 447LIBRARY IS WITH YOU. SHOULD THE LIBRARY PROVE DEFECTIVE, YOU ASSUME 448THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. 449 450 16. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN 451WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY 452AND/OR REDISTRIBUTE THE LIBRARY AS PERMITTED ABOVE, BE LIABLE TO YOU 453FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR 454CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE 455LIBRARY (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING 456RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A 457FAILURE OF THE LIBRARY TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF 458SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH 459DAMAGES. 460 461 END OF TERMS AND CONDITIONS 462 463 How to Apply These Terms to Your New Libraries 464 465 If you develop a new library, and you want it to be of the greatest 466possible use to the public, we recommend making it free software that 467everyone can redistribute and change. You can do so by permitting 468redistribution under these terms (or, alternatively, under the terms 469of the ordinary General Public License). 470 471 To apply these terms, attach the following notices to the library. 472It is safest to attach them to the start of each source file to most 473effectively convey the exclusion of warranty; and each file should 474have at least the "copyright" line and a pointer to where the full 475notice is found. 476 477 478 <one line to give the library's name and a brief idea of what it does.> 479 Copyright (C) <year> <name of author> 480 481 This library is free software; you can redistribute it and/or 482 modify it under the terms of the GNU Lesser General Public 483 License as published by the Free Software Foundation; either 484 version 2.1 of the License, or (at your option) any later version. 485 486 This library is distributed in the hope that it will be useful, 487 but WITHOUT ANY WARRANTY; without even the implied warranty of 488 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 489 Lesser General Public License for more details. 490 491 You should have received a copy of the GNU Lesser General Public 492 License along with this library; If not, see <http://www.gnu.org/licenses/>. 493 494Also add information on how to contact you by electronic and paper mail. 495 496You should also get your employer (if you work as a programmer) or 497your school, if any, to sign a "copyright disclaimer" for the library, 498if necessary. Here is a sample; alter the names: 499 500 Yoyodyne, Inc., hereby disclaims all copyright interest in the 501 library `Frob' (a library for tweaking knobs) written by James 502 Random Hacker. 503 504 <signature of Ty Coon>, 1 April 1990 505 Ty Coon, President of Vice 506 507That's all there is to it! 508 509 510