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\part{A Practical Guide to GPL Compliance}

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This part is: \\

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

Copyright \= \copyright{} 2008 \= \hspace{.2in} Software Freedom Law Center. \\

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\vspace{1in}

Authors of this part are: \\

Bradley M. Kuhn \\

Aaron Williamson \\

Karen M. Sandler \\

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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

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

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\chapter*{Executive Summary}

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

License (GPL) and related licenses. In accordance with the Software

Freedom Law Center's (SFLC's) philosophy of assisting the community with

GPL compliance cooperatively, this guide focuses on avoiding compliance

actions and minimizing the negative impact when enforcement actions occur.

It 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}

Early GPL enforcement efforts began soon after the GPL was written by

Richard Stallman 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

permission to modify the work to add a conditional requirement.  Namely,

downstream users may only have permission to modify  the work if they pass

along the same permissions on the modified version that came originally to

them.

These original program-specific proto-GPLs give an interesting window into

the central ideas and development of copyleft.  In particular, reviewing them

shows how the text of the GPL we know has evolved to address more of the

issues discussed earlier in \S~\ref{software-and-non-copyright}.

\section{The GNU General Public License, Version 1}

In January 1989, the FSF announced that the GPL had been converted into a

``subroutine'' that could be reused not just for all FSF-copyrighted

programs, but also by anyone else.  As the FSF claimed in its announcement of

the GPLv1\footnote{The announcement of GPLv1 was published in the

  \href{http://www.gnu.org/bulletins/bull6.html\#SEC8}{GNU'S Bulletin, vol 1,

    number 6 dated January 1989}.  (Thanks very much to Andy Tai for his

  \href{http://www.free-soft.org/gpl_history/}{consolidation of research on

    the history of the pre-v1 GPL's}.)}:

\begin{quotation}

To make it easier to copyleft programs, we have been improving on the

legalbol architecture of the General Public License to produce a new version

that serves as a general-purpose subroutine: it can apply to any program

without modification, no matter who is publishing it.

\end{quotation}

This, like many inventive ideas, seems somewhat obvious in retrospect.  But,

the FSF had some bright people and access to good lawyers when it started.

It took almost five years from the first copyleft licenses to get to a

generalized, reusable GPLv1.  In the context and mindset of the 1980s, this

is not surprising.  The idea of reusable licensing infrastructure was not

only uncommon, it was virtually nonexistent!  Even the early BSD licenses

were simply copied and rewritten slightly for each new use\footnote{It

  remains an interesting accident of history that the early BSD problematic

  ``advertising clause'' (discussion of which is somewhat beyond the scope of

  this tutorial) lives on into current day, simply because while the

  University of California at Berkeley gave unilateral permission to remove

  the clause from \textit{its} copyrighted works, others who adapted the BSD

  license with their own names in place of UC-Berkeley's never have.}.  The

GPLv1's innovation of reuable licensing infrastructure, an obvious fact

today, was indeed a novel invention for its day\footnote{We're all just

  grateful that the FSF also opposes business method patents, since the FSF's

  patent on a ``method for reusable licensing infrastructure'' would have

  not expired until 2006!}.

\section{The GNU General Public License, Version 2}

\section{The GNU General Public License, Version 3}

\section{The Innovation of Optional ``Or Any Later'' Version}

\section{Complexities of Two Simultaneously Popular Copylefts}

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\chapter{GPLv2: Running Software and Verbatim Copying}

\label{run-and-verbatim}

This chapter begins the deep discussion of the details of the terms of

GPLv2\@. In this chapter, we consider the first two sections: GPLv2 \S\S

0--2. These are the straightforward sections of the GPL that define the

simplest rights that the user receives.

\section{GPLv2 \S 0: Freedom to Run}

\label{GPLs0}

\S 0, the opening section of GPLv2, sets forth that the work is governed by

copyright law. It specifically points out that it is the ``copyright

holder'' who decides if a work is licensed under its terms and explains

how the copyright holder might indicate this fact.

A bit more subtly, \S 0 makes an inference that copyright law is the only

system under which it is governed. Specifically, it states:

\begin{quote}

Activities other than copying, distribution and modification are not

covered by this License; they are outside its scope.

\end{quote}

In essence, the license governs \emph{only} those activities, and all other

activities are unrestricted, provided that no other agreements trump GPLv2

(which they cannot; see Sections~\ref{GPLs6} and~\ref{GPLs7}). This is

very important, because the Free Software community heavily supports

users' rights to ``fair use'' and ``unregulated use'' of copyrighted

material. GPLv2 asserts through this clause that it supports users' rights

to fair and unregulated uses.

Fair use of copyrighted material is an established legal doctrine that

permits certain activities. Discussion of the various types of fair

use activity are beyond the scope of this tutorial. However, one

important example of fair use is the right to quote a very few lines

(less than seven or so) and reuse them as you would with or without

licensing restrictions.

Fair use is a doctrine established by the courts or by statute. By

contrast, unregulated uses are those that are not covered by the statue

nor determined by a court to be covered, but are common and enjoyed by