diff --git a/gpl-lgpl.tex b/gpl-lgpl.tex index b278627..f6d2bd5 100644 --- a/gpl-lgpl.tex +++ b/gpl-lgpl.tex @@ -492,56 +492,65 @@ of this work itself). Copyright holders of creative work can unilaterally implement these licenses for their own works to build communities that collaboratively share and improve those copylefted creative works. -% FIXME-URGENT: integrate -Copyleft, -which uses functional parts of copyright law to achieve an unusual result -(legal protection for free sharing) forms the core legal principle of these -licenses. It modifies, or ``hacks'' copyright law, which is usually employed to -strengthen the rights of authors or publishers, to strengthen instead the -rights of users. %FIXME-URGENT: end -Copyleft is a legal strategy and mechanism to defend, uphold and propagate software +Copyleft uses functional parts of the copyright system to achieve an unusual +result (legal protection for free sharing). Copyleft modifies, or ``hacks'' +copyright law, which is usually employed to strengthen the rights of authors +or publishers, to strengthen instead the rights of users. Thus, Copyleft is +a legal strategy and mechanism to defend, uphold and propagate software freedom. The basic technique of copyleft is as follows: copyright the -software, license it under terms that give all the software freedoms, but -use the copyright law controls to ensure that all who receive a copy of -the software have equal rights and freedom. In essence, copyleft grants -freedom, but forbids others to forbid that freedom to anyone else along -the distribution and modification chains. +software, license it under terms that give all the software freedoms, but use +the copyright law controls to ensure that all who receive a copy of the +software have equal rights and freedom. In essence, copyleft grants freedom, +but forbids others to forbid that freedom to anyone else along the +distribution and modification chains. -% FIXME-URGENT: integrate - -This ``reciprocity'' or ``share and share alike'' rule protects both +Copyleft's ``reciprocity'' or ``share and share alike'' rule protects both developers, who avoid facing a ``proprietized'' competitor of their project, -and users, who can be sure that they will have all four basic freedoms not -only in the present version of the program they use, but in all its future -improved versions. +and users, who can be sure that they will have all four software freedoms --- +not only in the present version of the program they use, but in all its +future improved versions. -% FIXME-URGENT: integrate - -The unit of copyright law is ``the work''. In that sense, the ``work'' -referenced by the licenses is anything that can be copyrighted or will be -subject to the terms of copyright law. The GNU licenses exercise their scope -fully. Anything which is ``a work'' or a ``work based on a work'' licensed -under GPL is subject to its requirements, including the requirement of -complete and corresponding source code, unless it is specifically -excepted. This principle often causes theoretical or speculative dispute -among lawyers, because ``the work'' is not a unit of computer programming. In -order to determine whether a ``routine'' an ``object'', a ``function'', a -``library'' or any other unit of software is part of one ``work'' when combined -with other GPL’d code, we must ask a question that copyright law will not -directly answer in the same technical terms. - -The key here is that the GNU GPL licenses mean to ``plow fence row to fence -row'', covering every version of ``work based on the work'' recognized by local -copyright law, but no further. - -%FIXME-URGENT: end Copyleft is a general concept. Much like ideas for what a computer might do must be \emph{implemented} by a program that actually does the job, so too must copyleft be implemented in some concrete legal structure. ``Share and share alike'' is a phrase that is used often enough to explain the concept behind copyleft, but to actually make it work in the real world, a -true implementation in legal text must exist. The GPL is the primary -implementation of copyleft in copyright licensing language. +true implementation in legal text must exist, written as a ``copyright +license''. The GPL implements the concept of copyleft for software-oriented +and other functional works of a technical nature. The ``CC BY SA'' license +implements copyleft for works of textual, musical and visual authorship, such +as this tutorial. + +Copyleft advocates often distinguish between the concept of a ``strong +copyleft'' or a ``weak copyleft''. However, ``strong vs. weak'' copyleft is +not a dichotomy, it's a spectrum. The strongest copylefts strive to the +exclusive rights that copyright grants to authors as extensively as possible +to maximize software freedom. As a copyleft gets ``weaker'', the copyleft +license typically makes ``trade offs'' that might impede software freedom, +but reach other tactic goals for the community of users and developers of the +work. + +In other words, strong copyleft licenses place the more requirements on how +``the work'' is licensed. The unit of copyright law is ``the work''. In +that sense, the ``work'' referenced by the licenses is anything that can be +copyrighted or will be subject to the terms of copyright law. Strong +copyleft licenses exercise their scope fully. Anything which is ``a work'' +or a ``work based on a work'' licensed under a strong copyleft is subject to +its requirements, including the requirement of complete, corresponding source +code\footnote{Copyleft communities' use of the term ``strong copyleft'' is + undoubtedly imprecise. For example, most will call the GNU GPL a ``strong + copyleft'' license, even though the GPL itself has various exceptions, such + as the \hyperref[GPLv3-system-library-exception]{GPLv3's system library + exception} written into the text of the license itself. Furthermore, the + copyleft community continues to debate where the a license cross the line + from ``strong copyleft'' to ``license that fails to respect software + freedom'', although ultimately these debates are actually regarding whether + the license fits \hyperref[Free Software Definition]{Free Software + definition} at all.}. Thus, copyleft licenses, particularly strong ones, +seek to ensure the same license covers every version of ``work based on the +work'', as recognized by local copyright law, and thereby achieve the +specific strategic policy aim of ensuring software freedom for all users, +developers, authors, and readers who encounter the copylefted work. \subsection{Software and Non-Copyright Legal Regimes} \label{software-and-non-copyright} @@ -1176,6 +1185,16 @@ on making a profit from Free Software redistribution.) \chapter{Derivative Works: Statute and Case Law} \label{derivative-works} +% FIXME-URGENT: integrate +This principle often causes theoretical or +speculative dispute among lawyers, because ``the work'' is not a unit of +computer programming. In order to determine whether a ``routine'' an +``object'', a ``function'', a ``library'' or any other unit of software is +part of one ``work'' when combined with other GPL’d code, we must ask a +question that copyright law will not directly answer in the same technical +terms. (This issue +%END FIXME-URGENT + We digress for this chapter from our discussion of GPL's exact text to consider the matter of derivative works --- a concept that we must understand fully before considering GPLv2~\S\S2--3\@. The GPL, and Free @@ -2701,6 +2720,7 @@ 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. \subsection{The System Library Exception} +\label{GPLv3-system-library-exception} The previous section skipped over one part of the CCS definition, the so-called system library exception. The ``System Libraries'' definition (and