由于研究的需要，要比较详细地了解GNU公共许可的一些细节。网络上流行的基本上是英文版的，中文版的比较少，找到一篇但是看了一下好像大多是经过软件翻译出来的，不过总体上还可以，但有些方面就影响理解GNU公共许可的原意，所以我就对照着英文版的在原来的基础上根据自己的理解重新核对和修改了一下，希望有意者也修改一下。
因为很多人对GNU的声明和各种条款知之甚少，或者理解有些片面化，但是我们要更有效得利用这些开源资源并贡献自己的力量，这些开源的规则我们还是得了解的。希望大家看了之后能提出好的修改意见。下面首先是中文版的，接着是英文版的。
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GNU 较宽松公共许可
1999年2月，版本2.1
版权所有 (C) 1991, 1999 Free Software Foundation, Inc.
59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
原文网站: http://www.gnu.org/licenses/lgpl.html
(巫细波修改翻译于2007-12-24)
这是一份 GNU 较宽松公共许可非正式的中文翻译。它不是自由软体基金会所发布，并且不能适用于使用 GNU LGPL 的软体 —— 只有 GNU LGPL 英文原文的版本才行。然而，我们希望这份翻译能帮助中文的使用者更了解 GNU LGPL，让更多使用中文的开源爱好者能够有效利用Internet上的开源项目。
注意：允许每个人复制和发布本授权文件的完整副本，但不允许对它进行任何修改。
[这是第一次发表的较宽松公共许可证 (Lesser GPL) 版本。它同时也可视为 GNU 函数库公共许可证 (GNU Library Public License) 第 2 版的后继者，故称为 2.1 版]
导言
大多数软件的版权声明可以剥夺您共享和修改软体的自由。相反的，GNU 通用公共许可会力图保证您共享和修改自由软体的自由 — 保证自由软件对所有使用者都是自由的。
这个许可证即“较宽松公共许可证”，适用于一些由自由软体基金会与其他决定使用此许可证的软件作者设计的软件包 — 特别是函数库。您也可以使用它，但我们建议您事先仔细考虑以下的说明，然后决定一下：是否此许可证或原来的通用公共许可证在任何特殊情况下均为较好的方案。
当我们谈到自由软件时，我们所指的是软件使用的自由，而不是从价格的角度来说。我们的 GNU 通用公共许可证设计出来是用以确保使您有发布自由软件拷贝的自由（如果您愿意，您可以对此项服务收取一定的费用），确保您能收到程序源代码或者在您需要时能得到它，确保您能修改软件或将它的一部分用于新的自由软件，而且还确保您知道您可以做上述的这些事情。
为了保护您的权利，我们需要做出限制：禁止任何人否认您的上述权利，或者要求您放弃这些权利。如果您发布了软件的副本，或者对得到的副本作了修改，这些规定就转化为您的责任。例如，如果您发布了此函数库的副本，不管是免费还是收取费用，您必须将您享有的一切权利给予接受者；您必须确保他们也能收到或得到程序源代码；如果您将此函数库与其他的代码连结，您必须提供完整的文件给接受者，使他们可以修改此函数库并重新编译过后，可以重新与文档连结。同时您要将这些条款给他们看，使他们知道他们有这样的权利。
我们采取两项措施来保护您的权利:
（1）用版权来保护函数库；
（2）我们提供给您这份许可证，赋予您复制，发布和（或）修改这些函数库的法律许可。
为了保护每个发布者，我们需要非常清楚地让每个人明白，自由函数库是没有担保责任的。如果由于某人修改了函数库，并继续加以传播，我们需要它的接受者明白：他们所得到的并不是原始的版本，因此由其他人引入的任何问题，对原作者的声誉将不会有任何的影响。最后，由于专利软件不断地威胁自由软件的存在，我们希望商业公司无法通过专利持有方去取得一个受限的许可证，而加以限制自由软件的使用者。因此，我们坚持一个函数库所能取得的任何专利，必须与本许可证所声明的“完全自由使用”达成一致。
大部分的 GNU 软件，包括一些函数库，是受到原来的 GNU 通用公共许可证的保护。本许可证即GNU 较宽松通用公共许可证，适用于一些特别的函数库，且与原来的通用公共许可证有很大的不同。我们在特定的函数库中使用它，以允许非开源的程序可以与这些函数库连结。 当一个程序与一个函数库连结，不论是静态连结或使用共享函数库，二者的结合可以合理地说是结合的作品，是一个原来的函数库的衍生品。而原来的通用公共许可证只有在整个结合品满足其自由的标准时，才允许连结。较宽松通用公共许可证则以更宽松的标准允许其他非开源程序代码与这些函数库连结。
我们称此许可证为 "较宽松" 通用公共许可证，是因为它比起原来的通用公共许可证对使用者的自由做到较少的保护。在与非自由软件竞争时，它也提供给其他自由软件的作者较少的优势，而这些不利之处的存在正是我们依然将原来的通用公共许可证使用在许多函数库的理由。然而，较宽松的许可证可在某些特殊场合下带来好处。 例如，在少数情况下，可能会有特殊的需要而鼓励大家尽可能广泛地使用特定的函数库，因而使它成为实际上的标准。为了达到此目标，必须允许非自由的程序使用此函数库。一个较常发生的情况是一个自由的函数库与一个被广泛使用的商业函数库有相同的功能，在此情况下，限制只有自由软体才可以使用这个自由函数库将不会带来多少好处，所以我们如用了较宽松通用公共许可证。
在其他情况下，允许非自由程序使用特定的函数库，可以让更多的人们使用大部分的自由软件。例如，允许非自由程序使用 GNU C 函数库，从而可以吸引更多的人去使用整个 GNU操作系统以及它的变形：GNU/Linux 操作系统。
尽管较宽松通用共公许可证对使用者的自由是较少的保护的，它却能确保与此函数库连结的程序的使用者拥有自由和必要保证去使用修改过的函数库版本来执行程序。
以下是复制、发布、以及修改的精确条款与声明。请注意 "基于函数库的作品" 以及 "使用函数库的作品" 之间的差异：前者包含来自函数库修改过的源代码；而后者则必须与函数库配合才能运行。
GNU 较宽松通用公共许可证有关复制，发布和修改的条款和声明
0. 本许可证适用于任何软件函数库，或其他包含了由版权所有者加入的注意事项的程序，或其他有可信度的团体宣称其程序可以在较宽松通用公共许可证 (也称之为 "本许可证") 的条款下发布。每一位许可证接受者以 "您" 来称呼。
一个 "函数库" 意指一些软件函数的集合以及/或相关的数据，以方便与应用程序 (其使用了其中某些函数与数据) 连结形成可执行的程序。
以下，"函数库" 一词指的是任何遵守本条款发布的一类软件函数库或作品，一个 "基于本函数库的作品" 意指函数库或任何在版权法下的衍生作品：也就是说，一个包含了本函数库或其一部分的作品，可以是原封不动的，或经过修改的，和/或直接翻译成其他语言的。(在下文中，翻译是不受限地包含在 "修改" 的条款中。)
作品的 "源代码" 意指对作品进行修改最初择取的形式。对函数库而言，完整的源代码意指所有模块的所有源代码，以及有关接口的定义，加上控制函数库的安装和编译的脚本。
本许可证条款不适用于复制，发布和修改以外的活动，这些活动超出这些条款的范围。使用本函数库来执行本程序的行为不受此条款的限制，而程序的输出只有在其内容所构成的作品是基于本函数库时 (与在什么样的工具中使用本函数库来输出无关) ，这一条款才适用。是否符合以上条件则取决于本函数库具体用来做什么。
1. 只要您在每一程序副本上明显和恰当地宣告版权声明和不承担担保的声明，并保持此许可证的声明和没有担保的声明完整无损，并和程序一起给其他每位程序接受者一份许可证的副本，您就可以用任何媒体复制和发布您收到的函数库的完整源代码。您可以为转让副本的实际行动收取一定费用。您也可以选择提供担保以换取一定的费用。
2. 只要您同时满足下面的所有条件，您就可以按前面第一款的要求修改函数库的一个或几个副本或它的任何部分，以此形成基于此函数库的作品，并且复制和发布这一经过修改的程序或作品:
a)被修改的作品本身必须是一个软件函数库。
b)您必须在修改过的档案中附有明确的说明：您修改了此档案及任何修改的日期。
c)您必须让整个作品允许第三方在此许可证条款下可以免费使用。
d)如果修改过的函数库中的某个功能引用了使用此功能的应用程序中的某个其它函数或数据表格，但不是当此功能被调用时要传入的参数，则您必须确保做到，当某个应用程序不提供这样的函数或数据表格时，此功能依旧能工作，且其执行的任何目的仍然是有意义的。(例如，一个函数库有个函数用来计算平方根，这个函数有一个与具体应用程序无关的、完整的定义。因此,第2小节中要求：由应用程序所提供的函数或数据必须是可选的：如果应用程序不提供的话，则计算平方根的函数必须依旧能计算平方根)。
这些要求适用于整个修改过的作品。如果能够确定作品的一部分并非本函数库的衍生产品，且可以合理地单独考虑并将它与原作品分开的话，则当您将它作为独立的作品发布时，它不受此许可证和其条款的约束。但是当您将这部分与基于本函数库的作品一同发布时，则整个组件将受到本许可证条款约束，其对于其他许可证持有人的使用范围扩大到整个产品，也就是组件的每个部分，不管它是谁写的。
因此，本条款的意图不在于索取权利或剥夺完全由您完成的作品的权利，而是履行权利来控制基于本函数库的作品集或衍生作品的发布。 此外，将与本函数库无关的作品和本函数库 (或基于本函数库的作品)一起放在贮存介质或发布媒体的同一卷上，并不导致将其他作品置于此许可证的约束范围之内。
3. 对于一个函数库的副本，您可以选择性地使用原来的 GNU 通用公共许可证上的条款来取代本许可证上的条款。如果您要这么做，您必须修改所有引用本许可证的注意事项，使它们指向原来的 GNU 通用公共许可证，第二版，以取代本许可证(如果有比第二版的原来的 GNU 通用公共许可证更新的版本出现的话，则如果您愿意的话可以特别指明使用新版)。请不要对这些注意事项做出其他的改变。
一旦在一个副本上做了这样的改变，则该副本就无法撤回这样的改变，故原来的 GNU 通用公共许可证将适用于所有后续的副本以及由此副本衍生出来的作品。这种选择适用于当您想要将一部分的函数库原始码复制到一个非函数库的程序使用时。
4. 您可以采取代码的形式或可执行文件的形式复制或发布函数库 (或符合第 2 款，基于本函数库的作品)，只要您遵守前面的第 1、2 款，并同时提供完整的相关机器可读的源代码，而这些源代码必须在前面的第 1 款与第 2 款条件下，在一般习惯上用来做软件交换的媒体上发布。
如果所发布的代码是由指定的地点提供拷贝索取，那么由同一地点所提供等价的源代码拷贝索取可以算作源代码的发布，即使第三方不强求与目标码一起复制源代码。
5. 一个程序若包含不经任何部分修改的函数库，但却是设计经由编译或连结的方式与函数库协同工作，称之为 "使用函数库的作品"。这样的一个作品，严格地说，并非本函数库的衍生作品，因而不在本许可证的范围之内。
然而，将 "使用函数库的作品" 与函数库（衍生自原来的函数库）连结而产生可执行程序，则是函数库的衍生品 (因为它包函了本函数库的一部分)，而不是 "使用函数库的作品"，因此其可执行程序包含在本许可证的范围内。第 6 款说明了发布此可执行程序的条款。
当 "使用函数库的作品" 使用了函数库部分的标头档内容时，则此作品即使其源代码不属于本函数库的衍生品，但其代码仍然是。是否符合以上条件则要看本作品是否可以在不需要本函数库即可连结，或者是否该作品本身也是一个函数库时特别明显。
如果这样的目标档只使用数字参数、数据结构与访问器、以及少量宏和内联函数(小于或等于十行) ，则此目标文件的使用是不受限的，不论是否它是合法的衍生作品。 (但可执行程序若包函此目标文件以及一部分的函数库，仍然将在第 6 款的规定下)。
否则的话，如果本作品是本函数库的衍生品，您必须在第 6 款的规定下发布该作品的目标码。任何包含该作品的可执行程序也在第 6 款的范围内，不论它们是否直接与函数库连结。
6. 做为上述条款的例外情况，您也可以将 "使用函数库的作品" 与函数库结合或连结，以产生包含部分函数库的作品，并在允许使用者自身使用时可以修改该作品，以及为调试修改而进行的反向工程，您可以依照您的选择发布该作品。
您必须在每个作品的副本突显出如下的注意事项：函数库在作品中被使用，以及函数库以及它的使用是在本许可证的规定下。您必须提供本许可证的副本。如果该作品在执行时显示版权声明，您必须在其中包含本函数库的版权声明，以及指引使用者取得本许可证的副本。同时，您必须做到以下其中一件事：
a)必须将完整的机器可读的函数库源代码包含在该作品中，包括任何该作品使用到的改变 (这些改变必须在前述第 1 与第 2 款的要求下发布)；而且，如果该作品是一个与函数库连结的、完整的、机器可读的 "使用函数库的作品"，则要有目标码和/或源代码，如此使用者可以修改函数库并且可以重新连结，以产生包含修改过的函数库的修改过的可执行程序。 (理所当然的若使用者修改了函数库的档案定义内容时，则该作品不必重新编译以使用修改过的定义。)
b)在与函数库连结时使用适当的分享函数库连结机制。一个适当的机制是： (1) 在执行时使用已存在于使用者的电脑中的函数库副本，而不是将函数库的函数复制到可执行程序里，以及 (2) 如果使用者安装了一份修改过的函数库，只要修改过的版本在接口层次上与该作品在编译连结时所用的版本是相容的，则该执行程序可以与修改过的函数库运作良好。
c)在该作品内提供书面报价，有效期不少于三年，以提供同样的使用者上述第 6a 款中的内容，费用不得超过该程序发布的实际成本。
d)如果所发布的作品是由指定的地点提供拷贝获取，则由同一地点提供上述内容的等价拷贝索取。
e)确定使用者已经收到该作品的一份复制，或是您已经寄给该使用者一份复制品。
对于一个可执行程序，其所需的 "使用函数库的作品" 的形式必须包括任何要从中再产生可执行程式时所需的资料与工具程序。然而，有一个特殊例外，其所发布的内容不需要包括任何一般与运行可执行程序的操作系统的主要部分 (如编译器、内核等) 一起发布的部分 (不论是源代码或可执行文件)，除非这些组成部分和可执行文件结合在一起。
有一个可能情况是，这些要求与其他通常不与操作系统在一起的私有函数库的版权限制相抵触，这样的抵触表示您不能将它们与函数库一起用于您发布的可执行程序中。
7. 您可以将使用函数库的函数库功能，以及其他不在本许可证范围内的函数库，对等地放入一个单独的函数库中，并在基于本函数库的作品以及其他函数库在其他状态下同意可以个别发布，以及您做到以下两点的情况下，您可以发布此结合的函数库：
将基于本函数库的作品单独不与其他函数库功能结合地，与此结合的函数库一同发布。该作品必须在上述条款的规定下发布。
在此结合的函数库中明显地指出其中一部分的作品是基于本函数库，并且说明那里可以找到同样不具结合形式的作品。
8. 除非您明确按许可证提出的要求去做，否则您不能复制、修改、转发许可证、与本函数库连结、和发布本函数库。任何试图用其他方式复制、修改、转发许可证、与本函数库连结、和发布本函数库是无效的，而且将自动结束许可证赋予您的权利。然而，对那些从您那里按许可证条款得到副本和权利的人们，只要他们继续全面履行条款，许可证赋予他们的权利仍然有效。
9. 您没有在许可证上签字，因而您没有必要一定接受许可证。然而，没有任何其他东西赋予您修改和发布函数库及其衍生作品的权利。如果您不接受许可证，这些行为是法律禁止的。因此，如果您修改或发布函数库 (或任何基于函数库的作品) ，您就表明您接受这一许可证以及它的所有有关复制、发布和修改本函数库或基于它的作品的条款和条件。
10. 每当您重新发布函数库 (或任何基于函数库的作品) 时，接受者自动从原始许可证颁发者那里接到受这些条款和条件支配的复制、发布、连结或修改本函数库的许可。您不可以强迫接受者履行除了这里赋予他们的权利之外的其他限制。您也没有强求第三方履行许可证条款的义务。
11. 如果由于法院判决或违反专利的指控或任何其他原因 (不限于专利问题) 的结果，使得强加于您的条件 (不管是法院判决，协议书或其他) 和许可证的条件有冲突时，他们也不能令您背离许可证的条款。在您不能同时满足本许可证规定的义务及其他相关的义务来发布函数库时，则结果您只能够根本不发布函数库。例如，如果某一专利许可证不允许所有直接或间接从您那里接受副本的人们，在不付专利费的情况下重新发布函数库，唯一能同时满足两方面要求的办法是停止发布函数库。
如果本条款的任何部分在特定的环境下无效或无法实施，就使用条款的其余部分，并将这部分条款作为整体用于其他环境。 本条款的目的不在于引诱您侵犯专利或其他财产权的要求，或争论这种要求的有效性。本条款的主要目的在于保护自由软件发布系统的完整性。它是通过公共许可证的应用来实现的。许多人已依赖同是出自此系统的应用程序，经由此系统发布大量自由软件而做出慷慨的供献。作者/捐献者有权决定他/她是否通过任何其他系统发布软件，许可证持有人不能强加这种选择。
本节的目的在于明确说明许可证其余部分可能产生的结果。
12. 如果由于专利或者由于有版权的界面问题使函数库在某些国家的发布和使用受到限制，则在许可证约束下的原始版权拥有者可以增加发布地区的限制条款，将这些国家明确排除在外，并在这些国家以外的地区发布函数库。在这种情况下，许可证组件包含的限制条款和许可证正文一样有效。
13. 自由软体基金会可能随时出版较宽松通用公共许可证的修改版或新版。新版和当前的版本在原则上保持一致，但在提到新问题时或有关事项时，在细节上可能出现差别。
每一版本都有不同的版本号。如果函数库指定可适用的许可证版本号以及 "任何更新的版本" ，您有权选择遵循指定的版本或自由软体基金会以后出版的新版本。如果函数库未指定许可证版本，您可选择自由软体基金会已经出版的任何版本。
14. 如果您愿意将函数库的一部分结合到其他自由程序中，而它们的发布条件不同，请写信给作者，要求准予使用。如果是自由软体基金会加以版权保护的软件，写信给自由软件基金会，我们有时会作为例外的情况处理。我们的决定受两个主要目标的指导，这两个主要目标是：我们的自由软件的衍生作品继续保持自由状态，以及从整体上促进软件的共享和重复利用，但是没有担保。
15. 由于函数库准予免费使用，在适用法准许的范围内，对函数库没有担保。除非另有书面说明，版权所有者和/或其他提供函数库的人们 "一样" 不提供任何类型的担保，不论是明确的，还是隐含的，包括但不限于可销售和适合特定用途的隐含保证。全部的风险，如函数库的质量和性能问题都由您来承担。如果函数库出现缺陷，您应当承担所有必要的服务、修复和改正的费用。
16. 除非适用法或书面协议的要求，在任何情况下，任何版权所有者或任何按许可证条款修改和发布函数库的人们都不对您的损失负有任何责任。包括由于使用或不能使用函数库引起的任何一般的、特殊的、偶然发生的或重大的损失 (包括但不限于数据的损失，或者数据变得不精确，或者您或第三方的持续的损失，或者函数库不能和其他软件协调运行等) 。即使版权所有者和其他人提到这种损失的可能性也不例外。
-条文结束-
-----------------------------------------------------------------------------------------------------------------
如何将这些条款用到您新的函数库
如果您开发了新函数库，而且您需要它得到公众最大限度的利用，要做到这一点的最好办法是将它变为自由软件，使每个需要这个函数库的人都能在遵守本条款 (或者是在原来的通用公共许可证的条款) 的基础上对它进行修改和重新发布。
为了做到这一点，请将函数库附上下列声明。最安全的方式是将它放在每个原始码档案的开头，以便最有效地传递拒绝担保的信息。每个文件至少应有 "版权所有" 行以及在什么地方能看到声明全文的说明。
用一行空间描述函数库的名称和它的用途简单说明
---------------------------------------------------------------------------
版权所有 (C) 19XX 作者姓名
这一函数库是自由软件，您可以遵照自由软体基金会出版的 GNU 较宽松通用公共许可证条款来修改和重新发布这一程序，或者用许可证的第二版，或者 (根据您的选择) 用任何更新的版本。
发布这一函数库的目的是希望它有用，但没有任何担保。甚至没有适合特定目的而隐含的担保。更详细的情况请参阅 GNU 较宽松通用公共许可证。
您应该已经在收到函数库的时候一起收到了一份 GNU 较宽松通用公共许可证的副本。如果还没有，写信给：
Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
-----------------------------------------------------------------------------
此外还应加上如何藉由电子邮件或一般信件与您保持联系的信息。
如果需要，您应该取得您的上司 (如果您是程序员) 或您的学校签署放弃函数库版权的声明。下面只是一个例子，您应该改变相应的名称：
***** 公司以此方式放弃 ***** 所写的 `****' 函数库 (用以扭转 **** 的函数库) 的全部版权利益。
***** 签名，2007-12-24
**** 副总裁
全部就只有这样了!
--------------------------------------------------------------------------------
英文版如下:
GNU LESSER GENERAL PUBLIC LICENSE
Version 2.1, February 1999
Copyright (C) 1991, 1999 Free Software Foundation, Inc.51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.
[This is the first released version of the Lesser GPL. It also counts as the successor of the GNU Library Public License, version 2, hence the version number 2.1.]
Preamble
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GNU LESSER GENERAL PUBLIC LICENSE TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
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