% compliance-guide.tex                            -*- LaTeX -*-

\part{A Practical Guide to GPL Compliance}

\label{gpl-compliance-guide}

{\parindent 0in

This part is: \\

\begin{tabbing}

Copyright \= \copyright{} 2008, 2014 \= \hspace{.2in} Bradley M. Kuhn. \\

Copyright \= \copyright{} 2014 \> \hspace{.2in} Free Software Foundation, Inc. \\

Copyright \> \copyright{} 2008, 2014 \> \hspace{.2in} Software Freedom Law Center. \\

\end{tabbing}

\vspace{.1in}

\begin{center}

The copyright holders of this part hereby grant the freedom to copy, modify,

convey, Adapt, and/or redistribute this work under the terms of the Creative

Commons Attribution Share Alike 4.0 International License.  A copy of that

license is available at

\url{https://creativecommons.org/licenses/by-sa/4.0/legalcode}.

\vfill

CC-By-SA-licensed published works: \\

\begin{itemize}

\item \hrefnofollow{http://www.softwarefreedom.org/resources/2008/compliance-guide.html}{\textit{The Practical Guide GPL Compliance}}, by Bradley M. Kuhn, Aaron

Williamson and Karen Sandler, first published on 2008-08-20. \\

\item \hrefnofollow{http://www.softwarefreedom.org/resources/2014/SFLC-Guide_to_GPL_Compliance_2d_ed.html}{\textit{Software Freedom Law Center Guide to GPL Compliance, 2nd

  Edition}} by Eben Moglen and Mishi Choudhary, first published on 2014-10-31. \\

\end{itemize}

However, this work is primarily composed of the many contributions it

receives as a public, collaborative project.  Please

\href{https://gitorious.org/copyleft-org/tutorial/history/master:compliance-guide.tex}{review

  its Git logs} for full documentation of all contributions.

\end{center}

}

\pagebreak

\chapter*{Executive Summary}

This is a guide to effective compliance with the GNU General Public

License (GPL) and related licenses.  Copyleft advocates

usually seek to assist the community with

GPL compliance cooperatively.   This guide focuses on complying from the

start, so that readers can learn to avoid enforcement actions entirely, or, at

least, minimize  the negative impact when enforcement actions occur.

This guide  introduces and explains basic legal concepts related to the GPL and its

enforcement by copyright holders. It also outlines business practices and

methods that lead to better GPL compliance.  Finally, it recommends proper

post-violation responses to the concerns of copyright holders.

\chapter{Background}

Copyright law grants exclusive rights to authors.  Authors who chose copyleft

seek to protect the freedom of users and developers to copy, share, modify

and redistribute the software.  However, copyleft is ultimately implemented

through copyright, and the GPL is primarily and by default a copyright

license.  (See \S~\ref{explaining-copyright} for more about the interaction

between copyright and copyleft.)  Copyright law grants an unnatural exclusive

control to copyright holders regarding copyright-controlled permissions

related to the work.  Therefore, copyright holders (or their agents) are the

ultimately the sole authorities to enforce copyleft and protect the rights of

users.  Actions for copyright infringement are the ultimate legal mechanism

for enforcement.  Therefore, copyright holders, or collaborative groups of

copyright holders, have historically been the actors in GPL enforcement.

The earliest of these efforts began soon after the GPL was written by

Richard M.~Stallman (RMS) in 1989, and consisted of informal community efforts,

often in public Usenet discussions.\footnote{One example is the public

  outcry over NeXT's attempt to make the Objective-C front-end to GCC

  proprietary.  RMS, in fact, handled this enforcement action personally and

  the Objective-C front-end is still part of upstream GCC today.}  Over the next decade, the Free Software Foundation (FSF),

which holds copyrights in many GNU programs, was the only visible entity

actively enforcing its GPL'd copyrights on behalf of the software freedom

community.

FSF's enforcement

was generally a private process; the FSF contacted violators

confidentially and helped them to comply with the license.  Most

violations were pursued this way until the early 2000's.

By that time, Linux-based systems such as GNU/Linux and BusyBox/Linux had become very common, particularly in

embedded devices such as wireless routers.  During this period, public

ridicule of violators in the press and on Internet fora supplemented

ongoing private enforcement and increased pressure on businesses to

comply.  In 2003, the FSF formalized its efforts into the GPL Compliance

Lab, increased the volume of enforcement, and built community coalitions

to encourage copyright holders to together settle amicably with violators.

Beginning in 2004, Harald Welte took a more organized public enforcement

approach and launched \href{http://gpl-violations.org/}{gpl-violations.org}, a website and mailing

list for collecting reports of GPL violations.  On the basis of these

reports, Welte successfully pursued many enforcement actions in Europe, including

formal legal action.  Harald earns the permanent fame as the first copyright

holder to bring legal action in a court regarding GPL compliance.

In 2007, two copyright holders in BusyBox, in conjunction with the

Software Freedom Conservancy (``Conservancy''), filed the first copyright infringement lawsuit

based on a violation of the GPL\@ in the USA. While  lawsuits are of course

quite public, the vast majority of Conservancy's enforcement actions 

are resolved privately via

cooperative communications with violators.  As both FSF and Conservancy have worked to bring

individual companies into compliance, both organizations have encountered numerous

violations resulting from preventable problems such as inadequate

attention to licensing of upstream software, misconceptions about the

GPL's terms, and poor communication between software developers and their

management.  This document highlights these problems and describe

best practices to encourage corporate Free Software users to reevaluate their

approach to GPL'd software and avoid future violations.

Both FSF and Conservancy continue GPL enforcement and compliance efforts

for software under the GPL, the GNU Lesser

Public License (LGPL) and other copyleft licenses.  In doing so, both organizations have

found that most violations stem from a few common, avoidable mistakes.  All copyleft advocates  hope to educate the community of

commercial distributors, redistributors, and resellers on how to avoid

violations in the first place, and to respond adequately and appropriately

when a violation occurs.

\section{Who Has Compliance Obligations?}

All distributors of modified or unmodified versions of copylefted works

unmodified versions of the works have compliance obligations.  Common methods

of modifying the works include innumerable common acts, such as:

\begin{itemize}

  \item embedding those works as executable copies

    into a device,

  \item transferring a digital copy of executable copies to someone else,

  \item posting a patch to the copylefted software to a public mailing list.

\end{itemize}

Such distributors have obligations to (at least) the users to whom they (or

intermediary parties) distribute those copies.  In some cases, distributors

have obligations to third parties not directly receiving their distribution

of the works (depending on the distributors chosen licensing options, as

described later in \S~\ref{binary-distribution-permission}).  In addition,

distributors have compliance obligations to upstream parties, such as

preservation of reasonable legal notices embedded in the code, and

appropriate labeling of modified versions.

Online service providers and distributors alike have other compliance

obligations.  In general, they must refrain from imposing any additional

restrictions on downstream parties. Most typically, such compliance problems

arise from ``umbrella licenses:'' EULAs, or sublicenses that restrict

downstream users' rights under copyleft. (See \S~\ref{GPLv2s6} and

\S~\ref{GPLv3s10}).

Patent holders having claims reading on GPL'd works they distribute must

refrain from enforcing those claims against parties to whom they distribute.

Furthermore, patent holders holding copyrights on GPLv3'd works must further

grant an explicit patent license for any patent claims reading on the version

they distributed, and therefore cannot enforce those specific patent claims

against anyone making, using or selling a work based on their distributed

version.  All parties must refrain from acting as a provider of services or

distributor of licensed works if they have accepted, or had imposed on them

by judicial action, any legal conditions that would prevent them from meeting

any obligation under GPL\@.  (See \S~\ref{GPLv2s7}, \S~\ref{GPLv3s11} and

\S~\ref{GPLv3s12}.

\section{What Are The Risks of Non-Compliance?}

Copyleft experts have for decades observed a significant mismatch between the

assumptions most businesses make about copyleft compliance and the realities.

Possibly due to excessive marketing of proprietary tools and services from

the for-profit compliance industry, businesses perennially focus on the wrong

concerns.  This tutorial seeks to educate those businesses about what

actually goes wrong, what causes disputes, and how to resolve those disputes.

Many businesses currently invest undue resources to avoid unlikely risks that

have low historical incidence of occurrence and low cost of remediation,

while leaving unmanaged the risks that have historically resulted in all the

litigation and other adverse outcomes.  For example, some ``compliance

industry''\footnote{``Compliance industry'' refers to third-party for-profit

  companies that market proprietary software tools and/or consulting services

  that purport to aid businesses with their Free Software license compliance

  obligations, such as those found in GPL and other copyleft licenses.  This

  tutorial leaves the term in quotes throughout, primarily to communicate the

  skepticism most of this tutorial's authors feel regarding the mere

  existence of this industry.  Not only do copyleft advocates object on

  principle to proprietary software tools in general, and to their ironic use

  specifically to comply with copyleft, but also to the ``compliance

  industry'' vendors' marketing messaging, which some copyleft advocates

  claim as a cause in the risk misassessments discussed herein.  Bradley

  M.~Kuhn, specifically, regularly uses the term ``compliance industrial

  complex''

  \href{http://en.wikipedia.org/wiki/Military-industrial_complex}{to

    analogize the types of problems in this industry to those warned against

    in the phrase of origin}.} vendors insist that great effort must be

expended to carefully list, in the menus or manuals of embedded electronics

products, copyright notices for every last copyright holder that contributed

to the Free Software included in the product.  While nearly all Free Software

licenses, including copylefts like GPL, require preservation and display of

copyright notices, failure to meet this specific requirement is trivially

remedied.  Therefore, businesses should spend just reasonable efforts to

properly display copyright notices, and note that failure to do so is simply

remedied: add the missing copyright notice!

\section{Understanding Who's Enforcing}

\label{compliance-understanding-whos-enforcing}

The mismatch between actual compliance risk and compliance risk management

typically results from a misunderstanding of licensor intentions.  For-profit

businesses often err by assuming other actors have kindred motivations.  The

primary enforcers of the GPL, however, have goals that for-profit businesses

will find strange and perhaps downright alien.

Specifically, community-oriented GPL enforcement organizations (called

``COGEOs'' throughout the remainder of this tutorial) are typically

non-profit charities (such as the FSF and Software Freedom Conservancy) who

%      Tutorial Text for the Detailed Study and Analysis of GPL and LGPL course

% License: CC-By-SA-4.0

% The copyright holders hereby grant the freedom to copy, modify, convey,

% Adapt, and/or redistribute this work under the terms of the Creative

% Commons Attribution Share Alike 4.0 International License.

% This text is distributed in the hope that it will be useful, but

% WITHOUT ANY WARRANTY; without even the implied warranty of

% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

% You should have received a copy of the license with this document in

% a file called 'CC-By-SA-4.0.txt'.  If not, please visit

% https://creativecommons.org/licenses/by-sa/4.0/legalcode to receive

% the license text.

\part{Case Studies in GPL Enforcement}

{\parindent 0in

This part is: \\

\begin{tabbing}

Copyright \= \copyright{} 2003, 2004, 2014 \hspace{1mm} \= \hspace{1.mm} \=  \kill

Copyright \> \copyright{} 2014 \>  Bradley M. Kuhn. \\

Copyright \> \copyright{} 2014 \>  Denver Gingerich \\

Copyright \> \copyright{} 2003, 2004, 2014 \> Free Software Foundation, Inc. \\

\end{tabbing}

\vspace{.2in}

\begin{center}

The copyright holders hereby grant the freedom to copy, modify, convey,

Adapt, and/or redistribute this work under the terms of the Creative Commons

Attribution Share Alike 4.0 International License.  A copy of that license is

available at \url{https://creativecommons.org/licenses/by-sa/4.0/legalcode}.

\end{center}

\vfill

CC-By-SA-licensed published works: \\

\begin{itemize}

\item \textit{Enforcement Case Studies}, written by Bradley M. Kuhn and published by the Free

  Software Foundation for its CLE courses  on 2004-01-20, 2004-08-24, and 2014-03-24.

\end{itemize}

However, this work is primarily composed of the many contributions it

receives as a public, collaborative project.  Please

\href{https://gitorious.org/copyleft-org/tutorial/history/master:enforcement-case-studies.tex}{review

  its Git logs} for full documentation of all contributions.

}

% =====================================================================

% START OF SECOND DAY SEMINAR SECTION

% =====================================================================

\chapter*{Preface}

This one-day course presents the details of five different GPL

compliance cases handled by FSF's GPL Compliance Laboratory. Each case

offers unique insights into problems that can arise when the terms of

the GPL are not properly followed, and how diplomatic negotiation between

the violator and the copyright holder can yield positive results for

both parties.

Attendees should have successfully completely the course, a ``Detailed

Study and Analysis of the GPL and LGPL,'' as the material from that

course forms the building blocks for this material.

This course is of most interest to lawyers who have clients or

employers that deal with Free Software on a regular basis. However,

technical managers and executives whose businesses use or distribute

Free Software will also find the course very helpful.

\bigskip

These course materials are merely a summary of the highlights of the

course presented. Please be aware that during the actual GPL course, class

discussion supplements this printed curriculum. Simply reading it is

not equivalent to attending the course.

%FIXME-LATER: write these

%\chapter{Not All GPL Enforcement is Created Equal}

%\section{For-Profit Enforcement}

%\section{Community and Non-Profit Enforcement}

\chapter{Overview of Community Enforcement}

The GPL is a Free Software license with legal teeth. Unlike licenses like

the X11-style or various BSD licenses, the GPL (and by extension, the LGPL) is

designed to defend as well as grant freedom. We saw in the last course

that the GPL uses copyright law as a mechanism to grant all the key freedoms

essential in Free Software, but also to ensure that those freedoms

propagate throughout the distribution chain of the software.

\section{Termination Begins Enforcement}

As we have learned, the assurance that Free Software under the GPL remains

Free Software is accomplished through various terms of the GPL: \S 3 ensures

that binaries are always accompanied with source; \S 2 ensures that the

sources are adequate, complete and usable; \S 6 and \S 7 ensure that the

license of the software is always the GPL for everyone, and that no other

legal agreements or licenses trump the GPL. It is \S 4, however, that ensures

that the GPL can be enforced.

Thus, \S 4 is where we begin our discussion of GPL enforcement. This

clause is where the legal teeth of the license are rooted. As a copyright

license, the GPL governs only the activities governed by copyright law ---

copying, modifying and redistributing computer software. Unlike most

copyright licenses, the GPL gives wide grants of permission for engaging with

these activities. Such permissions continue, and all parties may exercise

them until such time as one party violates the terms of the GPL\@. At the

moment of such a violation (i.e., the engaging of copying, modifying or

redistributing in ways not permitted by the GPL) \S 4 is invoked. While other

parties may continue to operate under the GPL, the violating party loses their

rights.

Specifically, \S 4 terminates the violators' rights to continue

engaging in the permissions that are otherwise granted by the GPL\@.

Effectively, their rights revert to the copyright defaults ---

no permission is granted to copy, modify, nor redistribute the work.

Meanwhile, \S 5 points out that if the violator has no rights under

the GPL, they are prohibited by copyright law from engaging in the

activities of copying, modifying and distributing. They have lost

these rights because they have violated the GPL, and no other license

gives them permission to engage in these activities governed by copyright law.

\section{Ongoing Violations}

In conjunction with \S 4's termination of violators' rights, there is

one final industry fact added to the mix: rarely does one engage in a

single, solitary act of copying, distributing or modifying software.

Almost always, a violator will have legitimately acquired a copy of a

GPL'd program, either making modifications or not, and then begun

distributing that work. For example, the violator may have put the

software in boxes and sold them at stores. Or perhaps the software

was put up for download on the Internet. Regardless of the delivery

mechanism, violators almost always are engaged in {\em ongoing\/}

violation of the GPL\@.

In fact, when we discover a GPL violation that occurred only once --- for

example, a user group who distributed copies of a GNU/Linux system without

source at one meeting --- we rarely pursue it with a high degree of

tenacity. In our minds, such a violation is an educational problem, and

unless the user group becomes a repeat offender (as it turns out, they

never do), we simply forward along a FAQ entry that best explains how user

groups can most easily comply with the GPL, and send them on their merry way.

It is only the cases of {\em ongoing\/} GPL violation that warrant our

active attention. We vehemently pursue those cases where dozens, hundreds

or thousands of customers are receiving software that is out of

compliance, and where the company continually offers for sale (or

distributes gratis as a demo) software distributions that include GPL'd

components out of compliance. Our goal is to maximize the impact of

enforcement and educate industries who are making such a mistake on a

large scale.

In addition, such ongoing violation shows that a particular company is

committed to a GPL'd product line. We are thrilled to learn that someone

is benefiting from Free Software, and we understand that sometimes they

become confused about the rules of the road. Rather than merely

giving us a postmortem to perform on a past mistake, an ongoing violation

gives us an active opportunity to educate a new contributor to the GPL'd

commons about proper procedures to contribute to the community.

Our central goal is not, in fact, to merely clear up a particular violation.

In fact, over time, we hope that our compliance lab will be out of

business. We seek to educate the businesses that engage in commerce

related to GPL'd software to obey the rules of the road and allow them to

operate freely under them. Just as a traffic officer would not revel in

reminding people which side of the road to drive on, so we do not revel in

violations. By contrast, we revel in the successes of educating an

ongoing violator about the GPL so that GPL compliance becomes a second-nature

matter, allowing that company to join the GPL ecosystem as a contributor.

\section{How are Violations Discovered?}

Our enforcement of the GPL is not a fund-raising effort; in fact, FSF's GPL

Compliance Lab runs at a loss (in other words, it is subsided by our

donors). Our violation reports come from volunteers, who have encountered,

in their business or personal life, a device or software product that

appears to contain GPL'd software. These reports are almost always sent

via email to $<$license-violation@fsf.org$>$.

Our first order of business, upon receiving such a report, is to seek

independent confirmation. When possible, we get a copy of the software

product. For example, if it is an offering that is downloadable from a

Web site, we download it and investigate ourselves. When it is not

possible for us to actually get a copy of the software, we ask the

reporter to go through the same process we would use in examining the

software.

By rough estimation, about 95\% of violations at this stage can be

confirmed by simple commands. Almost all violators have merely made an

error and have no nefarious intentions. They have made no attempt to

remove our copyright notices from the software. Thus, given the

third-party binary, {\tt tpb}, usually, a simple command (on a GNU/Linux

system) such as the following will find a Free Software copyright notice

and GPL reference:

\begin{quotation}

{\tt strings tpb | grep Copyright}

\end{quotation}

In other words, it is usually more than trivial to confirm that GPL'd

software is included.

Once we have confirmed that a violation has indeed occurred, we must then

determine whose copyright has been violated. Contrary to popular belief,

FSF does not have the power to enforce the GPL in all cases. Since the GPL

operates under copyright law, the powers of enforcement --- to seek

redress once \S 4 has been invoked --- lie with the copyright holder of

the software. FSF is one of the largest copyright holders in the world of

GPL'd software, but we are by no means the only one. Thus, we sometimes

discover that while GPL'd code is present in the software, there is no

software copyrighted by FSF present.

In cases where FSF does not hold copyright interest in the software, but

we have confirmed a violation, we contact the copyright holders of the

software, and encourage them to enforce the GPL\@. We offer our good offices

to help negotiate compliance on their behalf, and many times, we help as a

third party to settle such GPL violations. However, what we will describe

primarily in this course is FSF's first-hand experience enforcing its own

copyrights and the GPL\@.

\section{First Contact}

The Free Software community is built on a structure of voluntary

cooperation and mutual help. Our community has learned that cooperation

% gpl-lgpl.tex                                                  -*- LaTeX -*-

%      Tutorial Text for the Detailed Study and Analysis of GPL and LGPL course

%

% License: CC-By-SA-4.0

% The copyright holders hereby grant the freedom to copy, modify, convey,

% Adapt, and/or redistribute this work under the terms of the Creative

% Commons Attribution Share Alike 4.0 International License.

% This text is distributed in the hope that it will be useful, but

% WITHOUT ANY WARRANTY; without even the implied warranty of

% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

% You should have received a copy of the license with this document in

% a file called 'CC-By-SA-4.0.txt'.  If not, please visit

% https://creativecommons.org/licenses/by-sa/4.0/legalcode to receive

% the license text.

% FIXME-LATER: I should make a macro like the Texinfo @xref stuff for places

%      where I'm saying ``see section X in this tutorial'', so that the extra

%      verbiage isn't there in the HTML versions that I'll eventually do.

%      Maybe something like that already exists?  In the worst case, I could

%      adapt @xref from texinfo.texi for it.

\newcommand{\defn}[1]{\emph{#1}}

\part{Detailed Analysis of the GNU GPL and Related Licenses}

\label{gpl-lgpl-part}

{\parindent 0in

\tutorialpartsplit{``Detailed Analysis of the GNU GPL and Related Licenses''}{This part} is: \\

\begin{tabbing}

Copyright \= \copyright{} 2003--2007, 2014 \hspace{.1mm} \=  \kill

Copyright \> \copyright{} 2014 \> Bradley M. Kuhn \\

Copyright \> \copyright{} 2014 \>  Anthony K. Sebro, Jr. \\

Copyright \> \copyright{} 2003--2007, 2014 \>  Free Software Foundation, Inc. \\

Copyright \> \copyright{} 2014 \>  Software Freedom Law Center.

\end{tabbing}

\vspace{.2in}

\begin{center}

The copyright holders of \tutorialpartsplit{``Detailed Analysis of the GNU GPL and Related Licenses''}{this part} hereby grant the freedom to copy, modify,

convey, Adapt, and/or redistribute this work under the terms of the Creative

Commons Attribution Share Alike 4.0 International License.  A copy of that

license is available at

\verb=https://creativecommons.org/licenses/by-sa/4.0/legalcode=.

\end{center}

\vfill

CC-By-SA-licensed published works: \\

\begin{itemize}

\item \textit{Detailed Analysis of the GNU GPL and Related Licenses}, written by

Bradley M. Kuhn, Daniel B.~Ravicher, and John Sullivan and published by the Free Software Foundation for its CLE courses on 2004-01-20,

2004-08-24, and 2014-03-24.

\item \hrefnofollow{http://gplv3.fsf.org/gpl-rationale-2006-01-16.html}{\textit{GPLv3 First Discussion Draft Rationale}}, written and published by the Free

  Software Foundation on 2006-01-16.

\item \hrefnofollow{http://gplv3.fsf.org/opinions-draft-2.html}{\textit{GPLv3 Second Discussion Draft Rationale}}, written and published by the Free

  Software Foundation circa 2006-07.

\item \hrefnofollow{http://gplv3.fsf.org/gpl3-dd3-guide}{\textit{GPLv3 Third Discussion Draft Rationale}}, written and published by the Free

  Software Foundation on   2007-03-28.

\item \hrefnofollow{http://gplv3.fsf.org/dd3-faq}{\textit{GPLv3  Discussion Draft 3 FAQ}}, written and published by the Free1 Software Foundation on   2007-03-28.

\item \hrefnofollow{http://gplv3.fsf.org/gpl3-dd4-guide.html}{\textit{GPLv3 Final Discussion Draft Rationale}} written and published by the Free

  Software Foundation onon 2007-05-31.

\item \hrefnofollow{http://www.gnu.org/licences/gpl3-final-rationale.pdf}{\textit{GPLv3 Final Rationale}}, written and published by the Free

  Software Foundation on 2007-06-29.

\end{itemize}

However, this work is primarily composed of the many contributions it

receives as a public, collaborative project.  Please

\href{https://gitorious.org/copyleft-org/tutorial/history/master:gpl-lgpl.tex}{review

  its Git logs} for full documentation of all contributions.

}

\pagebreak

\tutorialpartsplit{This tutorial}{This part of the tutorial} gives a

comprehensive explanation of the most popular Free Software copyright

license, the GNU General Public License (``GNU GPL'', or sometimes just

``GPL'') -- both version 2 (``GPLv2'') and version 3 (``GPLv3'') -- and

teaches lawyers, software developers, managers and business people how to use

the GPL (and GPL'd software) successfully both as a community-building

``Constitution'' for a software project, and to incorporate copylefted

software into a new Free Software business and in existing, successful

enterprises.

To benefit from this part of the tutorial, readers should

have a general familiarity with software development processes.  A basic

understanding of how copyright law applies to software is also helpful.  The

tutorial is of most interest to lawyers, software developers and managers who

run or advise software businesses that modify and/or redistribute software

under the terms of the GNU GPL (or who wish to do so in the future), and those

who wish to make use of existing GPL'd software in their enterprise.

Upon completion of this part of the tutorial, readers can expect

to have learned the following:

\begin{itemize}

  \item The freedom-defending purpose of various terms in the GNU GPLv2 and GPLv3.

  \item The differences between GPLv2 and GPLv3.

  \item The redistribution options under the GPLv2 and GPLv3.

  \item The obligations when modifying GPLv2'd or GPLv3'd software.

  \item How to build a plan for proper and successful compliance with the GPL.

  \item The business advantages that the GPL provides.

  \item The most common business models used in conjunction with the GPL.

  \item How existing GPL'd software can be used in existing enterprises.

  \item The basics of LGPLv2.1 and LGPLv3, and how they

    differ from the GPLv2 and GPLv3, respectively.

  \item The basics to begin understanding the complexities regarding

    derivative and combined works of software.

\end{itemize}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% END OF ABSTRACTS SECTION

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% START OF DAY ONE COURSE

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\chapter{What Is Software Freedom?}

Study of the GNU General Public License (herein, abbreviated as \defn{GNU

  GPL} or just \defn{GPL}) must begin by first considering the broader world

of software freedom. The GPL was not created in a vacuum. Rather, it was

created to embody and defend a set of principles that were set forth at the

founding of the GNU project and the Free Software Foundation (FSF) -- the

preeminent organization that upholds, defends and promotes the philosophy of software

freedom. A prerequisite for understanding both of the popular versions

of the GPL

(GPLv2 and GPLv3) and their terms and conditions is a basic understanding of

the principles behind them.  The GPL family of licenses are unlike nearly all

other software licenses in that they are designed to defend and uphold these

principles.

\section{The Free Software Definition}

\label{Free Software Definition}

The Free Software Definition is set forth in full on FSF's website at

\verb0http://fsf.org/0 \verb0philosophy/free-sw.html0. This section presents

an abbreviated version that will focus on the parts that are most pertinent

to the GPL\@.

A particular user has software freedom with respect to a particular program if that

user has the following freedoms:

\begin{itemize}

\item The freedom to run the program, for any purpose.

\item The freedom to study how the program works, and modify it

\item The freedom to redistribute copies.

\item The freedom to distribute copies of  modified versions to others.

\end{itemize}

The focus on ``a particular user'' is particularly pertinent here.  It is not

uncommon for a subset of a specific program's user base to have these freedoms, while other

users of the same version the program have none or only some of these freedoms.

Section~\ref{Proprietary Relicensing} talks in detail about how

this can unfortunately happen even if a program is released under the GPL\@.

Many people refer to software with these freedoms as ``Open Source.''

Besides having a different political focus than those who call it Free

Software,\footnote{The political differences between the Free Software

  Movement and the Open Source Movement are documented on FSF's Web site at

  \url{http://www.fsf.org/licensing/essays/free-software-for-freedom.html}.}

Those who call the software ``Open Source'' are often focused on a side

issue.  Specifically, user access to the source code of a program is a

prerequisite to make use of the freedom to modify.  However, the important

issue is what freedoms are granted in the license of that source code.

Software freedom is only complete when no restrictions are imposed on how

these freedoms are exercised.  Specifically, users and programmers can

exercise these freedoms noncommercially or commercially.  Licenses that grant

these freedoms for noncommercial activities but prohibit them for commercial

activities are considered non-free.  Even the Open Source Initiative

(\defn{OSI}) (the arbiter of what is considered ``Open Source'') also rules

such licenses not in fitting with its ``Open Source Definition''.

In general, software for which any of these freedoms are

restricted in any way is called ``non-Free Software.''  Typically, the

term ``proprietary software'' is used more or less interchangeably with

``non-Free Software.''  Personally, I tend to use the term ``non-Free

Software'' to refer to noncommercial software that restricts freedom

(such as ``shareware'') and ``proprietary software'' to refer to

commercial software that restricts freedom (such as nearly all of

Microsoft's and Oracle's offerings).

Keep in mind that none of the terms ``software freedom'', ``open source''

and ``free software'' are known to be trademarked or otherwise legally

restricted by any organization in

any jurisdiction.  As such, it's quite common that these terms are abused and

misused by parties who wish to bank on the popularity of software freedom.

When one considers using, modifying or redistributing a software package that

purports to be Open Source or Free Software, one \textbf{must} verify that

the license grants software freedom.

Furthermore, throughout this text, we generally prefer the term ``software

freedom'', as this is the least ambiguous term available to describe software

that meets the Free Software Definition.  For example, it is well known and

often discussed that the adjective ``free'' has two unrelated meanings in

English: ``free as in freedom'' and ``free as in price''.  Meanwhile, the

term ``open source'' is even more confusing, because it appears to refer only to the

``freedom to study'', which is merely a subset of one of the four freedoms.

The remainder of this section considers each of each component of software

freedom in detail.

\subsection{The Freedom to Run}

\label{freedom-to-run}

The first tenet of software freedom is the user's fully unfettered right to

run the program.  The software's license must permit any conceivable use of

the software.  Perhaps, for example, the user has discovered an innovative

use for a particular program, one that the programmer never could have

predicted.  Such a use must not be restricted.

It was once rare that this freedom was restricted by even proprietary

software; but such is quite common today. Most End User License Agreements

(EULAs) that cover most proprietary software typically restrict some types of

uses.  Such restrictions of any kind are an unacceptable restriction on

software freedom.

\subsection{The Freedom to Change and Modify}

Perhaps the most useful right of software freedom is the users' right to

change, modify and adapt the software to suit their needs.  Access to the

source code and related build and installation scripts are an essential part

of this freedom.  Without the source code, and the ability to build and