\section{Appropriate Legal Notices}

GPLv2 used the term ``appropriate copyright notice and disclaimer of

warranty'' in two places, which is a rather bulk term.  Also, experience with

GPLv2 and other licenses that grant software freedom showed throughout the

1990s that the scope of types of notices that need preservation upon

conveyance were more broad that merely the copyright notices.  The

Appropriate Legal Notice definition consolidates the material that GPLv2

traditionally required preserved into one definition.

\section{Other Defined Terms}

Note finally that not all defined terms in GPLv3 appear in GPLv3~\S0.

Specifically, those defined terms that are confined in use to a single

section are defined in the section in which they are used, and GPLv3~\S1

contains those definitions focused on source code.  In this tutorial, those

defined terms are discussed in the section where they are defined and/or

used.

\section{GPLv3~\S1: Understanding CCS}

Ensuring that users have the source code to the software they receive and the

freedom to modify remains the paramount right embodied in the Free Software

Definition (found in \S~\ref{Free Software Definition} of this tutorial).  As

such, GPLv3~\S1 is likely one of the most important sections of GPLv3, as it

contains all the defined terms related to this important software freedom.

\subsection{Source Code Definition}

First, GPLv3\~S1 retains GPLv2's definition of ``source code'' and adds an

explicit definition of ``object code'' as ``any non-source version of a

work''.  Object code is not restricted to a narrow technical meaning and is

understood broadly to include any form of the work other than the preferred

form for making modifications to it.  Object code therefore includes any kind

of transformed version of source code, such as bytecode or minified

Javascript.  The definition of object code also ensures that licensees cannot

escape their obligations under the GPL by resorting to shrouded source or

obfuscated programming.

\subsection{CCS Definition}

The definition of CCS\footnote{Note that the preferred term for those who

  work regularly with both GPLv2 and GPLv3 is ``Complete Corresponding

  Source'', abbreviated to ``CCS''.  Admittedly, the word ``complete'' no

  longer appears in GPLv3 (which uses the word ``all'' instead).  However,

  both GPLv2 and the early drafts of GPLv3 itself used the word ``complete'',

  and early GPLv3 drafts even called this defined term ``Complete

  Corresponding Source''.  Meanwhile, use of the acronym ``CCS'' (sometimes,

  ``C\&CS'') was so widespread among GPL enforcers that its use continues

  even though GPLv3-focused experts tend to say just the defined term of

  ``Corresponding Source''.}, or, as GPLv3 officially calls it,

``Corresponding Source'' in GPLv3~\S1\P4 is possibly the most complex

definition in the license.

The CCS definition is broad so as to protect users' exercise of their rights

under the GPL\@.  The definition includes with particular examples to remove

any doubt that they are to be considered CCS\@.  GPLv3 seeks to make it

completely clear that a licensee cannot avoid complying with the requirements

of the GPL by dynamically linking a subprogram component to the original

version of a program.  The example also clarifies that the shared libraries

and dynamically linked subprograms that are included in Corresponding Source

are those that the work is ``specifically'' designed to require, which

clarifies that they do not include libraries invoked by the work that can be

readily substituted by other existing implementations.  While copyleft

advocates never doubted this was required under GPLv2's definition of CCS,

making it abundantly clear with an extra example.

GPL, as always, seeks to ensure users are truly in a position to install and

run their modified versions of the program; the CCS definition is designed to

be expansive to ensure this software freedom.  However, although the

definition of CCS is expansive, it is not sufficient to protect users'

freedoms in many circumstances.  For example, a GPL'd program, or a modified

version of such a program, might be locked-down and restricted.  The

requirements in GPLv3~\S6 (discussed in Section~\ref{GPLv3s6} of this

tutorial) handle that issue.  (Early drafts of GPLv3 included those

requirements in the definition of CCS; however, given that the lock-down

issue only comes up in distribution of object code, it is more logical to

place those requirements with the parts of GPLv3 dealing directly with object

code distribution).

The penultimate paragraph in GPLv3\S2 notes that GPLv3's CCS definition does

not require source that can be automatically generated.  Many code

generators, preprocessors and take source code as input and sometimes even

have output that is still source code.  Source code should always be whatever

the original programmer preferred to modify.

GPLv3\S1's final paragraph removes any ambiguity about what should be done on

source-only distributions.  Specifically, the right to convey source code

that does not compile, does not work, or otherwise is experimental

in-progress work is fully permitted, \textit{provided that} no object code

form is conveyed as well.  Indeed, when combined with the permissions in

GPLv3\S~5, it is clear that if one conveys \texti{only} source code, one can

never be required to provide more than that.  One always has the right to

modify a source code work by deleting any part of it, and there can be no

requirement that free software source code be a whole functioning program.

% FIXME: These don't belong here

It is important to note that section 11, paragraph 3 refers to a work that is

conveyed, and section 10, paragraph 2 refers to a kind of automatic

counterpart to conveying achieved as the result of a transaction. 

\section{GPLv3~\S2: Basic Permissions}

% FIXME: phrase ``unmodified Program'' appears due to User Products exception

We have included the first sentence of section 2 to further internationalize

the GPL. Under the copyright laws of some countries, it may be necessary for

a copyright license to include an explicit provision setting forth the

duration of the rights being granted. In other countries, including the

United States, such a provision is unnecessary but permissible.

The first paragraph of section 2 also acknowledges that licensees under the

GPL enjoy rights of copyright fair use, or the equivalent under applicable

law. These rights are compatible with, and not in conflict with, the freedoms

that the GPL seeks to protect, and the GPL cannot and should not restrict

them.

% FIXME: propagate and convey

Section 2 distinguishes between activities of a licensee that are permitted

without limitation and activities that trigger additional requirements. The

second paragraph of section 2 guarantees the basic freedoms of privately

modifying and running the program. However, the right to privately modify and

run the program is terminated if the licensee brings a patent infringement

lawsuit against anyone for activities relating to a work based on the

program.

% FIXME:  transition, and some word smith

The explicit prohibition of sublicensing ensures that enforcement of the GPL

is always by the copyright holder.  Usually, sublicensing is regarded as a

practical convenience or necessity for the licensee, to avoid having to

negotiate a license with each licensor in a chain of distribution.  The GPL

solves this problem in another way, through its automatic licensing

provision.

% FIXME: new section here, just to talk DRM before the other section.

GPLv3 introduces provisions that respond to the growing practice of

distributing GPL-covered programs in devices that employ technical means

to restrict users from installing and running modified versions.  This

practice thwarts the expectations of developers and users alike, because

the right to modify is one of the core freedoms the GPL is designed to

secure.

Technological measures to defeat users' rights --- often described by such

Orwellian phrases as ``digital rights management,'' which actually means

limitation or outright destruction of users' legal rights, or ``trusted

computing,'' which actually means selling people computers they cannot trust

--- are alike in one basic respect.  They all employ technical means to turn

the system of copyright law, where the powers of the copyright holder are

limited exceptions to general freedom, into a prison, where everything not

specifically permitted is utterly forbidden, and indeed, if the full extent

of their ambition is realized, would be technically impossible.  This system

of ``para-copyright'' has been created since the adoption of GPLv2, through

legislation in the United States, the European Union, and elsewhere that

makes it a serious civil or even criminal offense to escape from these

restrictions, even where the purpose in doing so is to restore the users'

legal rights that the technology wrongfully prevents them from exercising.

% FIXME: Remove FSF specific parts

As a digital rights organization, we would not be following our mission if we

did not oppose these injustices.  But the reason our license must respond to

these practices at all is the result of a remarkable irony. Those who wish to

impose DRM on the public would like to do so by using software covered by the

GPL, a license that is intended to preserve the very freedom that they seek

to crush.  They are not satisfied merely with publishing programs having

limited capability, which free software permits. They seek to go further, to

prevent the user from removing those limits, turning Freedom 1, the freedom

to modify, into a sham.

GPLv2 did not address the use of technical measures to take back the rights

that the GPL granted, because such measures did not exist in 1991, and would

have been irrelevant to the forms in which software was then delivered to

users.  But GPLv3 must address these issues: free software is ever more

widely embedded in devices that impose technical limitations on the user's

freedom to change it.

These unjust measures must not be confused with legitimate applications that

give users control, as by enabling them to choose higher levels of system or

data security within their networks, or by allowing them to protect the

security of their communications using keys they can generate or copy to

other devices for sending or receiving messages.  These technologies present

no obstacles to the freedom of free software. The user is presented with

choices, and figuratively as well as literally retains all the keys to the

digital home.

By contrast, technical restrictions that allow other parties to control the

user have no legitimate social purpose.  In existing applications where the

user is not afforded the same degree of real power to modify the free