| 1 | GNU LESSER GENERAL PUBLIC LICENSE | ||
| 2 | Version 2.1, February 1999 | ||
| 3 | |||
| 4 | Copyright (C) 1991, 1999 Free Software Foundation, Inc. | ||
| 5 | 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | ||
| 6 | Everyone is permitted to copy and distribute verbatim copies | ||
| 7 | of this license document, but changing it is not allowed. | ||
| 8 | |||
| 9 | [This is the first released version of the Lesser GPL. It also counts | ||
| 10 | as the successor of the GNU Library Public License, version 2, hence | ||
| 11 | the version number 2.1.] | ||
| 12 | |||
| 13 | Preamble | ||
| 14 | |||
| 15 | The licenses for most software are designed to take away your | ||
| 16 | freedom to share and change it. By contrast, the GNU General Public | ||
| 17 | Licenses are intended to guarantee your freedom to share and change | ||
| 18 | free software--to make sure the software is free for all its users. | ||
| 19 | |||
| 20 | This license, the Lesser General Public License, applies to some | ||
| 21 | specially designated software packages--typically libraries--of the | ||
| 22 | Free Software Foundation and other authors who decide to use it. You | ||
| 23 | can use it too, but we suggest you first think carefully about whether | ||
| 24 | this license or the ordinary General Public License is the better | ||
| 25 | strategy to use in any particular case, based on the explanations below. | ||
| 26 | |||
| 27 | When we speak of free software, we are referring to freedom of use, | ||
| 28 | not price. Our General Public Licenses are designed to make sure that | ||
| 29 | you have the freedom to distribute copies of free software (and charge | ||
| 30 | for this service if you wish); that you receive source code or can get | ||
| 31 | it if you want it; that you can change the software and use pieces of | ||
| 32 | it in new free programs; and that you are informed that you can do | ||
| 33 | these things. | ||
| 34 | |||
| 35 | To protect your rights, we need to make restrictions that forbid | ||
| 36 | distributors to deny you these rights or to ask you to surrender these | ||
| 37 | rights. These restrictions translate to certain responsibilities for | ||
| 38 | you if you distribute copies of the library or if you modify it. | ||
| 39 | |||
| 40 | For example, if you distribute copies of the library, whether gratis | ||
| 41 | or for a fee, you must give the recipients all the rights that we gave | ||
| 42 | you. You must make sure that they, too, receive or can get the source | ||
| 43 | code. If you link other code with the library, you must provide | ||
| 44 | complete object files to the recipients, so that they can relink them | ||
| 45 | with the library after making changes to the library and recompiling | ||
| 46 | it. And you must show them these terms so they know their rights. | ||
| 47 | |||
| 48 | We protect your rights with a two-step method: (1) we copyright the | ||
| 49 | library, and (2) we offer you this license, which gives you legal | ||
| 50 | permission to copy, distribute and/or modify the library. | ||
| 51 | |||
| 52 | To protect each distributor, we want to make it very clear that | ||
| 53 | there is no warranty for the free library. Also, if the library is | ||
| 54 | modified by someone else and passed on, the recipients should know | ||
| 55 | that what they have is not the original version, so that the original | ||
| 56 | author's reputation will not be affected by problems that might be | ||
| 57 | introduced by others. | ||
| 58 | |||
| 59 | Finally, software patents pose a constant threat to the existence of | ||
| 60 | any free program. We wish to make sure that a company cannot | ||
| 61 | effectively restrict the users of a free program by obtaining a | ||
| 62 | restrictive license from a patent holder. Therefore, we insist that | ||
| 63 | any patent license obtained for a version of the library must be | ||
| 64 | consistent with the full freedom of use specified in this license. | ||
| 65 | |||
| 66 | Most GNU software, including some libraries, is covered by the | ||
| 67 | ordinary GNU General Public License. This license, the GNU Lesser | ||
| 68 | General Public License, applies to certain designated libraries, and | ||
| 69 | is quite different from the ordinary General Public License. We use | ||
| 70 | this license for certain libraries in order to permit linking those | ||
| 71 | libraries into non-free programs. | ||
| 72 | |||
| 73 | When a program is linked with a library, whether statically or using | ||
| 74 | a shared library, the combination of the two is legally speaking a | ||
| 75 | combined work, a derivative of the original library. The ordinary | ||
| 76 | General Public License therefore permits such linking only if the | ||
| 77 | entire combination fits its criteria of freedom. The Lesser General | ||
| 78 | Public License permits more lax criteria for linking other code with | ||
| 79 | the library. | ||
| 80 | |||
| 81 | We call this license the "Lesser" General Public License because it | ||
| 82 | does Less to protect the user's freedom than the ordinary General | ||
| 83 | Public License. It also provides other free software developers Less | ||
| 84 | of an advantage over competing non-free programs. These disadvantages | ||
| 85 | are the reason we use the ordinary General Public License for many | ||
| 86 | libraries. However, the Lesser license provides advantages in certain | ||
| 87 | special circumstances. | ||
| 88 | |||
| 89 | For example, on rare occasions, there may be a special need to | ||
| 90 | encourage the widest possible use of a certain library, so that it becomes | ||
| 91 | a de-facto standard. To achieve this, non-free programs must be | ||
| 92 | allowed to use the library. A more frequent case is that a free | ||
| 93 | library does the same job as widely used non-free libraries. In this | ||
| 94 | case, there is little to gain by limiting the free library to free | ||
| 95 | software only, so we use the Lesser General Public License. | ||
| 96 | |||
| 97 | In other cases, permission to use a particular library in non-free | ||
| 98 | programs enables a greater number of people to use a large body of | ||
| 99 | free software. For example, permission to use the GNU C Library in | ||
| 100 | non-free programs enables many more people to use the whole GNU | ||
| 101 | operating system, as well as its variant, the GNU/Linux operating | ||
| 102 | system. | ||
| 103 | |||
| 104 | Although the Lesser General Public License is Less protective of the | ||
| 105 | users' freedom, it does ensure that the user of a program that is | ||
| 106 | linked with the Library has the freedom and the wherewithal to run | ||
| 107 | that program using a modified version of the Library. | ||
| 108 | |||
| 109 | The precise terms and conditions for copying, distribution and | ||
| 110 | modification follow. Pay close attention to the difference between a | ||
| 111 | "work based on the library" and a "work that uses the library". The | ||
| 112 | former contains code derived from the library, whereas the latter must | ||
| 113 | be combined with the library in order to run. | ||
| 114 | |||
| 115 | GNU LESSER GENERAL PUBLIC LICENSE | ||
| 116 | TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION | ||
| 117 | |||
| 118 | 0. This License Agreement applies to any software library or other | ||
| 119 | program which contains a notice placed by the copyright holder or | ||
| 120 | other authorized party saying it may be distributed under the terms of | ||
| 121 | this Lesser General Public License (also called "this License"). | ||
| 122 | Each licensee is addressed as "you". | ||
| 123 | |||
| 124 | A "library" means a collection of software functions and/or data | ||
| 125 | prepared so as to be conveniently linked with application programs | ||
| 126 | (which use some of those functions and data) to form executables. | ||
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| 128 | The "Library", below, refers to any such software library or work | ||
| 129 | which has been distributed under these terms. A "work based on the | ||
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| 135 | |||
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| 137 | making modifications to it. For a library, complete source code means | ||
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| 139 | interface definition files, plus the scripts used to control compilation | ||
| 140 | and installation of the library. | ||
| 141 | |||
| 142 | Activities other than copying, distribution and modification are not | ||
| 143 | covered by this License; they are outside its scope. The act of | ||
| 144 | running a program using the Library is not restricted, and output from | ||
| 145 | such a program is covered only if its contents constitute a work based | ||
| 146 | on the Library (independent of the use of the Library in a tool for | ||
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| 148 | and what the program that uses the Library does. | ||
| 149 | |||
| 150 | 1. You may copy and distribute verbatim copies of the Library's | ||
| 151 | complete source code as you receive it, in any medium, provided that | ||
| 152 | you conspicuously and appropriately publish on each copy an | ||
| 153 | appropriate copyright notice and disclaimer of warranty; keep intact | ||
| 154 | all the notices that refer to this License and to the absence of any | ||
| 155 | warranty; and distribute a copy of this License along with the | ||
| 156 | Library. | ||
| 157 | |||
| 158 | You may charge a fee for the physical act of transferring a copy, | ||
| 159 | and you may at your option offer warranty protection in exchange for a | ||
| 160 | fee. | ||
| 161 | |||
| 162 | 2. You may modify your copy or copies of the Library or any portion | ||
| 163 | of it, thus forming a work based on the Library, and copy and | ||
| 164 | distribute such modifications or work under the terms of Section 1 | ||
| 165 | above, provided that you also meet all of these conditions: | ||
| 166 | |||
| 167 | a) The modified work must itself be a software library. | ||
| 168 | |||
| 169 | b) You must cause the files modified to carry prominent notices | ||
| 170 | stating that you changed the files and the date of any change. | ||
| 171 | |||
| 172 | c) You must cause the whole of the work to be licensed at no | ||
| 173 | charge to all third parties under the terms of this License. | ||
| 174 | |||
| 175 | d) If a facility in the modified Library refers to a function or a | ||
| 176 | table of data to be supplied by an application program that uses | ||
| 177 | the facility, other than as an argument passed when the facility | ||
| 178 | is invoked, then you must make a good faith effort to ensure that, | ||
| 179 | in the event an application does not supply such function or | ||
| 180 | table, the facility still operates, and performs whatever part of | ||
| 181 | its purpose remains meaningful. | ||
| 182 | |||
| 183 | (For example, a function in a library to compute square roots has | ||
| 184 | a purpose that is entirely well-defined independent of the | ||
| 185 | application. Therefore, Subsection 2d requires that any | ||
| 186 | application-supplied function or table used by this function must | ||
| 187 | be optional: if the application does not supply it, the square | ||
| 188 | root function must still compute square roots.) | ||
| 189 | |||
| 190 | These requirements apply to the modified work as a whole. If | ||
| 191 | identifiable sections of that work are not derived from the Library, | ||
| 192 | and can be reasonably considered independent and separate works in | ||
| 193 | themselves, then this License, and its terms, do not apply to those | ||
| 194 | sections when you distribute them as separate works. But when you | ||
| 195 | distribute the same sections as part of a whole which is a work based | ||
| 196 | on the Library, the distribution of the whole must be on the terms of | ||
| 197 | this License, whose permissions for other licensees extend to the | ||
| 198 | entire whole, and thus to each and every part regardless of who wrote | ||
| 199 | it. | ||
| 200 | |||
| 201 | Thus, it is not the intent of this section to claim rights or contest | ||
| 202 | your rights to work written entirely by you; rather, the intent is to | ||
| 203 | exercise the right to control the distribution of derivative or | ||
| 204 | collective works based on the Library. | ||
| 205 | |||
| 206 | In addition, mere aggregation of another work not based on the Library | ||
| 207 | with the Library (or with a work based on the Library) on a volume of | ||
| 208 | a storage or distribution medium does not bring the other work under | ||
| 209 | the scope of this License. | ||
| 210 | |||
| 211 | 3. You may opt to apply the terms of the ordinary GNU General Public | ||
| 212 | License instead of this License to a given copy of the Library. To do | ||
| 213 | this, you must alter all the notices that refer to this License, so | ||
| 214 | that they refer to the ordinary GNU General Public License, version 2, | ||
| 215 | instead of to this License. (If a newer version than version 2 of the | ||
| 216 | ordinary GNU General Public License has appeared, then you can specify | ||
| 217 | that version instead if you wish.) Do not make any other change in | ||