@@ -328,116 +328,116 @@ software (For details of this in the USA, see
``public performance'' of copyrighted works. There is no generally agreed
definition for public performance of software and both GPLv2 and GPLv3 do
not govern public performance.} By law (in the USA and in most other
jurisdictions), the copyright holder (most typically, the author) of the work controls
how others may copy, modify and/or distribute the work. For proprietary
software, these controls are used to prohibit these activities. In addition,
proprietary software distributors further impede modification in a practical
sense by distributing only binary code and keeping the source code of the
software secret.
Copyright is not a natural state, it is a legal construction. In the USA, the
Constitution permits, but does not require, the creation of copyright law as
federal legislation. Software, since it is ``an original works of authorship
fixed in any tangible medium of expression ... from which they can be
perceived, reproduced, or otherwise communicated, either directly or with the
aid of a machine or device'' (as stated in
\href{http://www.law.cornell.edu/uscode/text/17/102}{USC 17 \S 102}), is thus
covered by the statues, and is copyrighted by default.
However, software, in its natural state without copyright, is Free
Software. In an imaginary world with no copyright, the rules would be
different. In this world, when you received a copy of a program's source
code, there would be no default legal system to restrict you from sharing it
with others, making modifications, or redistributing those modified
versions.\footnote{There could still exist legal systems, like our modern
patent system, which could restrict the software in other ways, as well as
technical measures, such as binary-only distribution, that impeded such activity.}
Software in the real world is copyrighted by default and is
automatically covered by that legal system. However, it is possible
to move software out of the domain of the copyright system. A
copyright holder can often \defn{disclaim} their
copyright. If copyright is disclaimed, the software is not governed
by copyright law. Software not governed by copyright is in the
``public domain.''
\subsection{Public Domain Software}
% FIXME: this section needs more improvements to make it clear that public
% domain dedication is difficult, if not impossible.
% Karen suggests that talking about USA government software being public
% domain might make sense here.
Theoretically, an author can create public domain software by disclaiming all
copyright interest on the work. In the USA and other countries that have
signed the Berne convention on copyright, software is copyrighted
automatically by the author when she ``fixes the software into a tangible
medium.'' In the software world, this usually means typing the source code
of the software into a file.
Imagine if an author can truly disclaim that default control given to her by the
copyright laws. Once this is done, the software is in the public domain
--- it is no longer covered by copyright. Since it is copyright law that
allows for various controls on software (i.e., prohibition of copying,
modification, and redistribution), removing the software from the
copyright system and placing it into the public domain does yield Free
Software.
Imagine if authors could truly disclaim those default control of copyright
law. If so, the software is in the public domain -- no longer covered by
copyright. Since copyright law is the construction allowing for most
restrictions on software (i.e., prohibition of copying, modification, and
redistribution), removing the software from the copyright system usually
yields software freedom for its users.
Carefully note that software in the public domain is \emph{not} licensed
in any way. It is nonsensical to say software is ``licensed for the
public domain,'' or any phrase that implies the copyright holder gave
expressed permission to take actions governed by copyright law.
By contrast, what the copyright holder has done is renounce her copyright
controls on the work. The law gave her controls over the work, and she
has chosen to waive those controls. Software in the public domain is
absent copyright and absent a license. The software freedoms discussed in
By contrast, the copyright holders instead renounced copyright controls on
the work. The law gave the copyright holder exclusive controls over the
work, and they chose to waive those controls. Software in the public domain
is absent copyright and absent a license. The software freedoms discussed in
Section~\ref{Free Software Definition} are all granted because there is no
legal system in play to take them away.
\subsection{Why Copyright Free Software?}
If simply disclaiming copyright on software yields Free Software, then it
stands to reason that putting software into the public domain is the
easiest and most straightforward way to produce Free Software. Indeed,
some major Free Software projects have chosen this method for making their
software Free. However, most of the Free Software in existence \emph{is}
copyrighted. In most cases (particularly in those of FSF and the GNU
Project), this was done due to very careful planning.
Software released into the public domain does grant freedom to those users
who receive the standard versions on which the original author disclaimed
copyright. However, since the work is not copyrighted, any nontrivial
modification made to the work is fully copyrightable.
Free Software released into the public domain initially is Free, and
perhaps some who modify the software choose to place their work into the
public domain as well. However, over time, some entities will choose to
proprietarize their modified versions. The public domain body of software
feeds the proprietary software. The public commons disappears, because
fewer and fewer entities have an incentive to contribute back to the
commons. They know that any of their competitors can proprietarize their
enhancements. Over time, almost no interesting work is left in the public
domain, because nearly all new work is done by proprietarization.
A legal mechanism is needed to redress this problem. FSF was in fact
originally created primarily as a legal entity to defend software freedom,
and that work of defending software freedom is a substantial part of
its work today. Specifically because of this ``embrace, proprietarize and
extend'' cycle, FSF made a conscious choice to copyright its Free Software,
and then license it under ``copyleft'' terms. Many, including the
developers of the kernel named Linux, have chosen to follow this paradigm.
Copyleft is a legal strategy 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.
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.