1 files changed, 263 insertions, 0 deletions
diff --git a/docs/licenses-introduction.md b/docs/licenses-introduction.md
new file mode 100644
index 0000000..21dbeff
--- /dev/null
+++ b/docs/licenses-introduction.md
@@ -0,0 +1,263 @@
+---
+Generator: 'texi2html 1.82'
+description: Untitled Document
+distribution: global
+keywords: Untitled Document
+resource-type: document
+title: Untitled Document
+...
+
+@begingroup @normalbottom @interlinepenalty = -200
+
+1. Introduction to the Licenses {#introduction-to-the-licenses .chapter}
+===============================
+
+@firstcopyingnotice{{Copyright © 2010 Free Software Foundation, Inc.\
+ {This essay is published in @fsfsthreecite} Written by Brett Smith and
+Richard Stallman.\
+ This part contains the text of the latest versions of the primary GNU
+licenses: the GNU General Public License (GNU GPL), the GNU Lesser
+General Public License (LGPL), and the GNU Free Documentation License
+(FDL). Though they are legal documents, they belong in this book of
+essays because they are concrete expressions of the ideals of free
+software.
+
+Software development for the GNU operating system began in 1984. Once
+Richard Stallman had parts of the GNU system that were worth releasing,
+he needed a license to release them under. Some free software licenses
+already existed; these gave users permission to modify and redistribute
+the software, but they also allowed using the code in proprietary
+versions and proprietary programs. Using those licenses, GNU would have
+failed to achieve its goal of delivering freedom to all users, because
+middlemen would have converted the GNU code into proprietary software.
+
+So Stallman devised a license to assure every user the freedom to modify
+and redistribute the software. It granted these permissions under one
+key condition: whoever distributed the software must pass along the
+authorization to modify and redistribute that same software, along with
+the source code making it practical to do so. Stallman coined the term
+“copyleft” (see “What Is Copyleft?” on @pageref{Copyleft}) to describe
+this key twist of using the legal power of copyright to ensure freedom
+for all users.
+
+GNU copyleft licenses were first developed for software, and later for
+related areas such as software documentation. In them, the principles of
+the free software movement, explained throughout the essays in this
+book, take practical form. Each of their successive revisions has had to
+wrestle with free software’s legal and practical obstacles and offers
+numerous illustrations of how free software ideals are codified into
+legal terms.
+
+### The Origins of the GPL {#the-origins-of-the-gpl .subheading}
+
+The first version of the GNU General Public License was published in
+1989—but Stallman had been releasing software under copyleft licenses as
+part of the GNU Project since as early as 1985. Prior to 1989, each
+published GNU program had been covered by a license specifically
+tailored for it. Instead of a single GNU General Public License, there
+was a GNU CC General Public License, a GDB General Public License, and
+so on. These licenses were identical except for minor differences: for
+instance, terms about displaying license notices to users were different
+for different programs and, unless it covered a program that was just
+one source file, each license contained the name of the program it
+applied to.
+
+By 1989, Stallman had had enough experience with different GNU packages
+under slightly different licenses to conclude that it was crucial to
+unify them into one license that would cover all these packages. He
+worked with Jerry Cohen, an attorney at Perkins Smith & Cohen LLP, to
+collect concepts from all the different licenses written up to that
+point, and bring them together into one license. It was thus that on
+1 February 1989 the GNU General Public License was born.
+
+The first version of the license sought to ensure two results: first,
+that all derived works of the software would be released under the same
+license and, second, that everyone who received the software would have
+a chance to get the source code. These requirements implement a strong
+copyleft by blocking the three main ways of making programs proprietary:
+with copyright, with end-user license agreements, and by not
+distributing source code.
+
+In comparison to the program-specific licenses that had preceded it, GPL
+version 1 featured few substantial changes—the GPL was evolutionary, not
+revolutionary—but it made a big practical difference. Previously,
+developers who had wanted to copyleft a program had needed to tailor one
+of the existing licenses to that program. Many had not bothered. With
+the release of the GPL, those developers had a license they could use
+out of the box to provide all of their users with freedom to share and
+change the software. It was a powerful tool.
+
+### Version 2 {#version2 .subheading}
+
+After the 1981 US Supreme Court decision in Diamond v. Diehr, the US
+Patent and Trademark Office began issuing patents for software. Software
+patents threaten free software and proprietary software alike (see part
+IV in this book), and Stallman realized that they could subvert the
+copyleft in the GNU GPL.
+
+By selectively issuing patent licenses, patent holders can arbitrarily
+control how the software under them is distributed or modified. A patent
+holder can give one party permission to resell the program, another
+permission to develop and use a modified version at her company, and a
+third permission to do all the activities that the GPL itself allows.
+They can demand whatever they wish in exchange for these permissions.
+They have this power over any software that implements the patented
+idea, whether or not they have modified or distributed it themselves.
+This power threatens free software because third parties with patents
+can impose restrictions on free software users and developers.
+
+If patent holders don’t distribute or modify software, then a software
+license based on copyright like the GPL can’t control their activities:
+they haven’t done anything that requires permission under the license.
+But the software license can stop each of the program’s distributors
+from entering limiting agreements with the patent holder. Enter GPL
+version 2: a new section in the license (sec. 7) explicitly says that if
+parties are subject to other legal agreements—such as a patent
+license—that contradict the GPL’s terms, then the licensee must refrain
+from distributing the software at all. As a result, any party that wants
+to distribute or modify the software, and also obtain a patent license,
+must ensure that the terms of that license are consistent with all of
+the GPL’s conditions: recipients of the software must receive it under
+the same terms, with no additional restrictions, and have the means to
+get the source code.
+
+This new section protected the integrity of the distribution system for
+GPL-covered software. A fundamental principle of the license is that
+every licensee, from the most humble individual to the largest
+corporation, has the exact same rights to share and change the software.
+Patent holders who do not distribute the software themselves and
+selectively issues patent licenses could potentially interfere with this
+goal, splitting licensees into different groups however they see fit.
+Section 7 of GPL version 2 prevents this abuse.
+
+### The LGPL {#the-lgpl .subheading}
+
+The GPL worked well for the programming tools, utilities, and games that
+were released by the GNU Project in the early years; however, Stallman
+recognized that releasing the recently developed GNU C Library the same
+way could backfire. Aside from some extensions, the GNU C Library was to
+be a compatible replacement for the Unix C Library, so any C program
+would be able link with either one. If proprietary C programs were not
+allowed to use the GNU C Library, they would simply use the Unix
+library. Being strict in this case would gain nothing.
+
+Stallman decided to compromise with a modified copyleft: one that would
+protect the freedom of the library itself, but not that of the programs
+that use it. This idea was implemented in a license originally called
+the GNU Library General Public License, first published as version 2.0,
+in June 1991. The original LGPL stated Conditions like the GPL’s—with an
+important exception: if someone else’s program used the library only by
+referring to it as a library, that program’s source could be distributed
+under license terms of the author’s choosing. However, the executable
+made by combining the program and the library had to come with a copy of
+the LGPL and source code for the library, and provide some mechanism for
+users who have modified the library to update the executable to use
+their modified library.
+
+How does a developer use the work as a library in order to take
+advantage of the special set of conditions provided by LGPLv2? Think of
+a computer program as a series of instructions for doing a particular
+job: compiling or linking the program with a library provides the
+programmer with a means to say, “When the program gets to this point,
+get further instructions from the library, and come back here when those
+are done.” Libraries are commonly used in software development because
+they make the effort less repetitive and less error prone: programmers
+don’t have to reinvent the wheel—and perhaps introduce bugs in the
+process—every time they want to accomplish a particular task. Because
+libraries are so widely created and used, developers have the means to
+readily take advantage of the LGPL’s additional permissions.
+
+Version 2.0 of the license worked as intended: in some situations,
+proprietary software developers chose to use an LGPL-covered library
+over a proprietary alternative, and users received the freedom to share
+and change that library. This did not produce an “ideal” outcome—where
+the user had complete control over the entire program—but in these cases
+the GPL would not have achieved that ideal outcome either. The LGPL
+assured the users some freedom where they would have otherwise had none.
+
+The name “Library GPL” led some free software developers to assume all
+libraries ought on principle to be licensed this way, but that was not
+the intent—when a free library has no proprietary competitor, releasing
+it under the GNU GPL can benefit free software. To avoid this unintended
+message, Stallman renamed this license to the Lesser General Public
+License, and incremented the version number to 2.1 to reflect the
+relatively minor changes in the text: the license sported a new
+preamble, a few wording clarifications, and allowed programs to make
+their calls to the library through special system facilities for shared
+libraries where those are available. The Lesser General Public License
+version 2.1 was released in February 1999.
+
+### The FDL {#the-fdl .subheading}
+
+At the turn of the century, free software was growing much faster than
+it had been previously; the documentation, however, was not keeping
+pace. Stallman was concerned about this failure and wrote about it in
+“Free Software Needs Free Documentation” (@pageref{Free Doc}).
+
+While there are some similarities between software and
+documentation—they are both works that are meant for practical use—there
+are important differences in the ways they can be used. The GPL and the
+LGPL were not suitable for manuals.
+
+For some time, GNU packages had been using an untitled, simple, ad hoc
+copyleft license for each manual. Since each manual’s license was
+different, text could not be copied from one manual to another. So
+Stallman wrote the GNU Free Documentation License, a copyleft license
+designed primarily for software documentation and other practical
+written works.
+
+The FDL was first published in March 2000. The principles of the
+copyleft remain the same: everyone who receives a copy of the work
+should be able to modify and redistribute it. Where the FDL differs from
+the software licenses is in the details of its implementation:
+conditions about how to attribute the work and provide “source code”—an
+editable version of the document—are different.
+
+### Version 3 {#version3 .subheading}
+
+During the 1990s, as free software became more popular, the GPL emerged
+as the clear copyleft license of choice for the community, and was
+adopted by the majority of free software projects; at the same time,
+however, proprietary developers had come up with methods of effectively
+denying users the freedoms that the GPL was meant to protect, without
+actually violating the GPL. In addition, there were other practices that
+the GPL did not handle conveniently. To deal with these issues called
+for an updated version of the license.
+
+Around 2002, Stallman and others at the Free Software Foundation began
+discussing how to update the GPL, and the LGPL along with it. The FSF
+established a public review process, run with help from attorneys at the
+Software Freedom Law Center, to catch possible problems before actually
+releasing the new licenses. Committees of advisors from the community
+studied issues raised by public comments and reported the various
+positions and arguments to Stallman, who decided what policy to adopt;
+then he wrote license text with advice and suggestions from the
+attorneys. The importance of the changes made are explained in “Why
+Upgrade to GPLv3” (@pageref{Why V3}).
+
+Version 3 used new terminology to promote uniform interpretations in
+different jurisdictions, and modified some requirements to fit new
+practices in the free software community. Beyond that, it introduced
+several new conditions to strengthen the copyleft and thereby the free
+software community as a whole. For instance, it
+
+-   blocked distributors from restricting users by building hardware
+    that rejects the users’ modified versions (“tivoization”);
+-   allowed code to carry limited additional requirements, for
+    compatibility with some other popular free software licenses;
+-   and strengthened patent requirements by providing clear terms to
+    handle patent cross-licenses, which are common arrangements between
+    large patent-holding companies.
+
+Both GPLv3 and LGPLv3 included terms to address all of these issues, and
+were finally released on 29 June 2007. These licenses are the state of
+the art in copyleft, going farther than any other software license to
+protect users’ freedom and bring about a world in harmony with the
+ideals expressed in this book.
+
+@endgroup
+
+------------------------------------------------------------------------
+
+This document was generated by *tonghuix* on *March 25, 2016* using
+[*texi2html 1.82*](http://www.nongnu.org/texi2html/).\