legal systems.  The GPL operates to grant this right to successive

generations of users, particularly through the copyleft conditions set

forth in section 5 of GPLv3, which applies to the conveying of works

based on the Program.  In section 0 we simply define a work based on

another work to mean ``any modified version for which permission is

necessary under applicable copyright law,'' without further qualifying

the nature of that permission, though we make clear that modification

includes the addition of material.\footnote{We have also removed the

paragraph in section 5 that makes reference to ``derivative or

collective works based on the Program.''}

%FIXME: transition

While ``covered by this license'' is a phrase found in GPLv2, defining it

more complete in a single as ``covered work'' enables some of the wording in

GPLv3 to be simpler and clearer than its GPLv2 counterparts.

% FIXME: does propagate  definition still work the same way in final draft?

The term ``propagate'' serves two purposes.  First, ``propagate'' provides a

simple and convenient means for distinguishing between the kinds of uses of a

work that the GPL imposes conditions on and the kinds of uses that the GPL

does not (for the most part) impose conditions on.

Second, ``propagate'' furthers our goal of making the license as global as

possible in its wording and effect.  When a work is licensed under the GPL,

the copyright law of some particular country will govern certain legal issues

arising under the license.  A term like ``distribute'' or its equivalent in

languages other than English, is used in several national copyright statutes.

Practical experience with GPLv2 revealed the awkwardness of using the

term ``distribution'' in a license intended for global use.  

The scope of ``distribution'' in the copyright context can differ from

country to country.  The GPL does not seek to necessarily use the specific

meaning of ``distribution'' that exists under United States copyright law or

any other country's copyright law.

%FIXME: rewrite, FSF third person,e tc.

Even within a single country and language, the term distribution may be

ambiguous; as a legal term of art, distribution varies significantly in

meaning among those countries that recognize it.  For example, we have been

told that in at least one country distribution may not include network

transfers of software but may include interdepartmental transfers of physical

copies within an organization.  In many countries the term ``making available

to the public'' or ``communicating to the public'' is the closest counterpart

to the generalized notion of distribution that exists under USA law.

Therefore, the GPL defines the term ``propagate'' by reference to activities

that require permission under ``applicable copyright law'', but excludes

execution and private modification from the definition.  GPLv3's definition

also gives examples of activities that may be included within ``propagation''

but it also makes clear that, under the copyright laws of a given country,

``propagation'' may include other activities as well.

% FIXME: probably merge this in

Propagation is defined by behavior, and not by categories drawn from some

particular national copyright statute.  We believe that such factually-based

terminology has the added advantage of being easily understood and applied by

individual developers and users.

% FIXME: transition here to convey definition, maybe with \subsection {},

%        also maybe with: Similar is true with the term ``convey''.

we have further internationalized the license by removing references to

distribution and replacing them with a new factually-based term,

``conveying.'' Conveying is defined to include activities that constitute

propagation of copies to others.  With these changes, GPLv3 addresses

transfers of copies of software in behavioral rather than statutory terms.

At the same time, we have acknowledged the use of ``making available to the

public'' in jurisdictions outside the USA by adding it as a specific example

in the definition of ``propagate.'' We decided to leave the precise

definition of an organizational licensee, and the line drawn between

licensees and other parties, for determination under local law.

% FIXME: paragraph number change , and more on Convey once definition comes.

The third paragraph of section 2 represents another effort to compensate for

variation in national copyright law.  We distinguish between propagation that

enables parties other than the licensee to make or receive copies, and other

forms of propagation.  As noted above, the meaning of ``distribution'' under

copyright law varies from country to country, including with respect to

whether making copies available to other parties (such as related public or

corporate entities) is ``distribution.'' ``Propagation,'' however, is a term

not tied to any statutory language.  Propagation that does not enable other

parties to make or receive copies --- for example, making private copies or

privately viewing the program --- is permitted unconditionally.  Propagation

that does enable other parties to make or receive copies is permitted as

``distribution,'' subject to the conditions set forth in sections 4--6.

% FIXME: Appropriate Legal Notices

\section{GPLv3~\S1: Understanding CCS}

% FIXME: Talk briefly about importance of CCS and reference compliance guide

% FIXME: verify this still matches final GPLv3 text.

% FIXME:  link to GPLv2 tutorial sections if possible and where appropriate.

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 to be

understood broadly as including 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.

% FIXME: CCS Coresponding Source updated to newer definition in later drafts

Keeping with the desire to ``round up'' definitions that were spread

throughout the text of GPLv2, the definition of CCS\footnote{Note that the

  preferred term by those who work 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 included the phrase

  ``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'', is given in GPLv3~\S1\P4.  This definition is as

broad as necessary to protect users' exercise of their rights under the

GPL\@.  We follow the definition with particular examples to remove any doubt

that they are to be considered Complete Corresponding Source Code.  We wish to

make completely clear that a licensee cannot avoid complying with the

requirements of the GPL by dynamically linking an add-on component to the

original version of a program.

Though the definition of Complete Corresponding Source Code in the

second paragraph of section 1 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 need to be

signed with a key or authorized with a code in order for it to run on

a particular machine and function properly. Similarly, a program that

produces digitally-restricted files might require a decryption code in

order to read the output.  

% FIXME: Standard Interface

% FIXME: System Libraries: it's in a different place and changed in later drafts

The final paragraph of section 1 revises the exception to the source code

distribution requirement in GPLv2 that we have sometimes called the system

library exception. This exception has been read to prohibit certain

distribution arrangements that we consider reasonable and have not sought to

prevent, such as distribution of gcc linked with a non-free C library that is

included as part of a larger non-free system. This is not to say that such

non-free libraries are legitimate; rather, preventing free software from

linking with these libraries would hurt free software more than it would hurt

proprietary software.

As revised, the exception has two parts. Part (a) rewords the GPLv2

exception for clarity but also removes the words ``unless that

component itself accompanies the executable.''  By itself, (a) would

be too permissive, allowing distributors to evade their

responsibilities under the GPL.  We have therefore added part (b) to

specify when a system library that is an adjunct of a major essential

operating system component, compiler, or interpreter does not trigger

the requirement to distribute source code.  The more low-level the

functionality provided by the library, the more likely it is to be

qualified for this exception.

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

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

We believe that these provisions, taken together, are a minimalist set of

terms sufficient to protect the free software community against the threat of

invasive para-copyright.

\section{GPLv3~\S3: What Hath DMCA Wrought}

\label{GPLv3s3}

% FIXME: reference the section in DMCA about this, maybe already there in

%        GPLv2 section?

% FIXME: Wrong paragraph now.

The second paragraph of section 3 declares that no GPL'd program is part of

an effective technological protection measure, regardless of what the program

does. Ill-advised legislation in the United States and other countries has

prohibited circumvention of such technological measures. If a covered work is

distributed as part of a system for generating or accessing certain data, the

effect of this paragraph is to prevent someone from claiming that some other

GPL'd program that accesses the same data is an illegal circumvention.

% FIXME: this needs rewritten 

In section 3, which has been retitled as well as redrafted, we have

specifically stated the rule, previously implicit, that modes of

distribution that establish limitations on use or modification that

are inconsistent with the terms of the license are not permitted by

the license.  In addition, we have added disclaimers, based on advice

of counsel from nations that have enacted para-copyright provisions

akin to the Digital Millennium Copyright Act in the US or pursuant to

the European Union Copyright Directive.  We believe these disclaimers

by each licensor of any intention to use GPL'd software to stringently

control access to other copyrighted works should practically prevent

any private or public parties from invoking DMCA-like laws against

users who escape technical restriction measures implemented by GPL'd

software.

\section{GPLv3~\S4: Verbatim Copying}

% FIXME: there appear to be minor changes here in later drafts, fix that.

Section 4 has been revised from its corresponding section in GPLv2 in light

of the new section 7 on license compatibility. A distributor of verbatim

copies of the program's source code must obey any existing additional terms

that apply to parts of the program. In addition, the distributor is required

to keep intact all license notices, including notices of such additional

terms.

\section{GPLv3~\S5: Modified Source}

% FIXME: 5(a) is slightly different in final version

Section 5 contains a number of changes relative to the corresponding section

in GPLv2. Subsection 5a slightly relaxes the requirements regarding notice of

changes to the program. In particular, the modified files themselves need no

longer be marked. This reduces administrative burdens for developers of

modified versions of GPL'd software.

Under subsection 5a, as in the corresponding provision of GPLv2, the notices

must state ``the date of any change,'' which we interpret to mean the date of

one or more of the licensee's changes.  The best practice would be to include

the date of the latest change.  However, in order to avoid requiring revision

of programs distributed under ``GPL version 2 or later,'' we have retained

the existing wording.

% FIXME:  It's now (b) and (c).  Also, ``validity'' of proprietary

%         relicensing?  Give me a break.  I'll fix that.

Subsection 5b is the central copyleft provision of the license.  It now

states that the GPL applies to the whole of the work.  The license must be

unmodified, except as permitted by section 7, which allows GPL'd code to be

combined with parts covered by certain other kinds of free software licensing

terms. Another change in subsection 5b is the removal of the words ``at no

charge,'' which was often misinterpreted by commentators.  The last sentence

of subsection 5b explicitly recognizes the validity of disjunctive

dual-licensing.

%  FIXME: 5d.  Related to Appropriatey Legal notices

% follows 5d now, call it the ``final paragraph''

The paragraph following subsection 5c has been revised for clarity, but the

underlying meaning is unchanged. When independent non-derivative sections are

distributed for use in a combination that is a covered work, the whole of the

combination must be licensed under the GPL, regardless of the form in which

such combination occurs, including combination by dynamic linking. The final

sentence of the paragraph adapts this requirement to the new compatibility

provisions of section 7.

\section{GPLv3~\S6: Non-Source and Corresponding Source}

Section 6 of GPLv3, which clarifies and revises GPLv2 section 3, requires

distributors of GPL'd object code to provide access to the corresponding

source code, in one of four specified ways. As noted above, ``object code''

in GPLv3 is defined broadly to mean any non-source version of a work.

% FIXME:  probably mostly still right, needs some updates, though.

New subsection 6d, which revises the final paragraph of GPLv2 section 3,

addresses distribution of object code by offering access to copy the code

from a designated place, such as by enabling electronic access to a network

server.  Subsection 6d clarifies that the distributor must offer equivalent

access to copy the source code ``in the same way through the same place.''

This wording permits a distributor to offer a third party access to both

object code and source code on a single network portal or web page, even

though the access may include links to different physical servers.  For

example, a downstream distributor may provide a link to an upstream

distributor's server and arrange with the operator of that server to keep the

source code available for copying for as long as the downstream distributor

enables access to the object code.  This codifies what has been our

interpretation of GPLv2.

%FIXME: 6e, peer-to-peer

%  FIXME: Not final paragraph anymore. 

The final paragraph of section 6 takes account of the fact that the Complete

Corresponding Source Code may include added parts that carry non-GPL terms,

as permitted by section 7.

% FIXME: update lock-down section to work with more recent drafts

Though the definition of Complete Corresponding Source Code in the second

paragraph of section 1 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 need to be signed with a key or authorized

with a code in order for it to run on a particular machine and function

properly. Similarly, a program that produces digitally-restricted files might

require a decryption code in order to read the output.

The third paragraph of section 1 addresses this problem by making clear that

Complete Corresponding Source Code includes any such encryption,

authorization, and decryption codes. By requiring the inclusion of this

information whenever the GPL requires distribution of Complete Corresponding

Source Code, we thwart efforts to obstruct the goals of the GPL, and we

ensure that users will remain in control over their own machines. We

recognize an exception where use of the program normally implies that the

user already has the codes. For example, in secure systems a computer owner

might possess any keys needed to run a program, while the distributor of the

program might not have the keys.

% FIXME: installation information

% FIXME: this came from Section 1 but is now mostly in Section 6

In section 1, we have tried to limit as precisely as possible the situation

in which an encryption or signing key is part of the Corresponding Source

Code of a GPL'd work.  Where someone is provided a GPL'd work, he must

receive the whole of the power to use and modify the work that was available

to preceding licensors whose permissions he automatically receives.  If a key

would be necessary to install a fully functional version of the GPL'd work

from source code, the user who receives the binary must receive the key along

with the source.  The requirement of full functionality, which we have

illustrated with examples, is no more optional than it would be if GPL'd

software were redistributed with an additional license condition, rather than

a technical limitation, on the uses to which modified versions could be

put.\footnote{There is a clear distinction between this situation and the

  situation of authenticated modules or plug-ins distributed as part of a

  multi-component software system, so that instances of the software can

  verify for the user the integrity of the collection.  So long as the

  decision about whether to run a modified version is the user's decision,

  not controlled by a preceding licensor or a third party, the vendor's

  authentication key would also not qualify as part of the Corresponding

  Source under the language we have adopted for Draft 2.}

\section{Understanding License Compatibility}

\label{license-compatibility}

% FIXME: more about license compatibility here.

A challenge that faced the Free Software community heavily through out the

early 2000s was the proliferation of incompatible Free Software licenses.  Of

course, we cannot make the GPL compatible with all such licenses. GPLv3

contains provisions that are designed to reduce license incompatibility by

making it easier for developers to combine code carrying non-GPL terms with

GPL'd code.

% FIXME: connecting text

\subsection{Additional Permissions}

% FIXME: rework and fix formatting.

The GPL is a statement of permissions, some of which have conditions.

Additional terms, terms that supplement those of the GPL, may come to be

placed on, or removed from, GPL-covered code in certain common ways.  We

consider those added terms ``additional permissions'' if they grant

exceptions from the conditions of the GPL, and ``additional requirements'' if

they add conditions to the basic permissions of the GPL. The treatment of

additional permissions and additional requirements under GPLv3 is necessarily

asymmetrical, because they do not raise the same ethical and interpretive

issues; in particular, additional requirements, if allowed without careful

limitation, could transform a GPL'd program into a non-free one.  With these

principles in the background, section 7 answers the following questions: (1)

How do the presence of additional terms on all or part of a GPL'd program

affect users' rights? (2) When and how may a licensee add terms to code being

distributed under the GPL? (3) When may a licensee remove additional terms?

% FIXME: FSF third person, etc.

Additional permissions present the easier case.  We have licensed some of our

own software under GPLv2 with permissive exceptions that allow combination

with non-free code, and that allow removal of those permissions by downstream

recipients; similarly, LGPLv2.1 is in essence a permissive variant of GPLv2,

and it permits relicensing under the GPL.  We have generalized these

practices in section 7.  A licensee may remove any additional permission from

a covered work, whether it was placed by the original author or by an

upstream distributor.  A licensee may also add any kind of additional

permission to any part of a work for which the licensee has, or can give,

appropriate copyright permission. For example, if the licensee has written

that part, the licensee is the copyright holder for that part and can

therefore give additional permissions that are applicable to it.

clear that enforcement of such requirements is expected to be by the

termination procedure given in section 8 of GPLv3.

% FIXME: better context, etc.

Some have questioned whether section 7 is needed, and some have suggested

that it creates complexity that did not previously exist.  We point out to

those readers that there is already GPLv2-licensed code that carries

additional terms.  One of the objectives of section 7 is to rationalize

existing practices of program authors and modifiers by setting clear

guidelines regarding the removal and addition of such terms.  With its

carefully limited list of allowed additional requirements, section 7

accomplishes additional objectives, permitting the expansion of the base of

code available for GPL developers, while also encouraging useful

experimentation with requirements we do not include in the GPL itself.

\section{GPLv3~\S8: A Lighter Termination}

% FIXME:  probably mostly still right, needs some updates, though.

GPLv2 provided for automatic termination of the rights of a person who

copied, modified, sublicensed, or distributed a work in violation of the

license.  Automatic termination can be too harsh for those who have committed

an inadvertent violation, particularly in cases involving distribution of

large collections of software having numerous copyright holders.  A violator

who resumes compliance with GPLv2 would need to obtain forgiveness from all

copyright holders, but even to contact them all might be impossible.

% FIXME: needs to be updated to describe more complex termination

Section 8 of GPLv3 replaces automatic termination with a non-automatic

termination process.  Any copyright holder for the licensed work may opt to

terminate the rights of a violator of the license, provided that the

copyright holder has first given notice of the violation within 60 days of

its most recent occurrence. A violator who has been given notice may make

efforts to enter into compliance and may request that the copyright holder

agree not exercise the right of termination; the copyright holder may choose

to grant or refuse this request.

% FIXME: needs to be updated to describe more complex termination

If a licensee who is in violation of GPLv3 acts to correct the violation and

enter into compliance, and the licensee receives no notice of the past

violation within 60 days, then the licensee need not worry about termination

of rights under the license.

\section{GPLv3~\S9: Acceptance}

\section{GPLv3~\S10: Explicit Downstream License}

\section{GPLv3~\S11: Explicit Patent Licensing}

\label{GPLv3s11}

% FIXME: just brought in words here, needs rewriting.

is rooted in the basic principles of the GPL.

Our license has always stated that distributors may not impose further

restrictions on users' exercise of GPL rights.  To make the suggested

distinction between contribution and distribution is to allow a

distributor to demand patent royalties from a direct or indirect

recipient, based on claims embodied in the distributed code. This

undeniably burdens users with an additional legal restriction on their

rights, in violation of the license.

%FIXME: possible useful text, but maybe not.

In the covenant provided in the revised section 11, the set of claims

that a party undertakes not to assert against downstream users are that

party's ``essential patent claims'' in the work conveyed by the party.

``Essential patent claims,'' a new term defined in section 0, are simply

all claims ``that would be infringed by making, using, or selling the

work.''  We have abandoned the phrase ``reasonably contemplated use.''

This change makes the obligations of distributing patent holders more

predictable.

% FIXME:  probably needs a lot of work, these provisions changed over time.

GPLv3 adds a new section on licensing of patents. GPLv2 relies on an implied

patent license. The doctrine of implied license is one that is recognized

under United States patent law but may not be recognized in other

jurisdictions. We have therefore decided to make the patent license grant

explicit in GPLv3. Under section 11, a redistributor of a GPL'd work

automatically grants a nonexclusive, royalty-free and worldwide license for

any patent claims held by the redistributor, if those claims would be

infringed by the work or a reasonably contemplated use of the work.

% FIXME:  probably needs a lot of work, these provisions changed over time.

The patent license is granted both to recipients of the redistributed work

and to any other users who have received any version of the work. Section 11

therefore ensures that downstream users of GPL'd code and works derived from

GPL'd code are protected from the threat of patent infringement allegations

made by upstream distributors, regardless of which country's laws are held to

apply to any particular aspect of the distribution or licensing of the GPL'd

code.

% FIXME:  probably needs a lot of work, these provisions changed over time.

A redistributor of GPL'd code may benefit from a patent license that has been

granted by a third party, where the third party otherwise could bring a

patent infringement lawsuit against the redistributor based on the

the final sentence of GPLv2 section 7, which we consider to be unnecessary.

\section{GPLv3~\S13: The Great Affero Compromise}

% FIXME

\section{GPLv3~\S14: So, When's GPLv4?}

\label{GPlv2s14}

% FIXME Say more

No substantive change has been made in section 14. The wording of the section

has been revised slightly to make it clearer.

% FIXME; proxy

\section{GPLv3~\S15--17: Warranty Disclaimers and Liability Limitation}

No substantive changes have been made in sections 15 and 16.

% FIXME: more, plus 17

% FIXME: Section header needed here about choice of law.

% FIXME: reword into tutorial

Some have asked us to address the difficulties of internationalization

by including, or permitting the inclusion of, a choice of law

provision.  We maintain that this is the wrong approach.  Free

software licenses should not contain choice of law clauses, for both

legal and pragmatic reasons.  Choice of law clauses are creatures of

contract, but the substantive rights granted by the GPL are defined

under applicable local copyright law. Contractual free software

licenses can operate only to diminish these rights.  Choice of law

clauses also raise complex questions of interpretation when works of

software are created by combination and extension.  There is also the

real danger that a choice of law clause will specify a jurisdiction

that is hostile to free software principles.

% FIXME: reword into tutorial, \ref to section 7.

Our revised version of section 7 makes explicit our view that the

inclusion of a choice of law clause by a licensee is the imposition of

an additional requirement in violation of the GPL.  Moreover, if a

program author or copyright holder purports to supplement the GPL with

a choice of law clause, section 7 now permits any licensee to remove

that clause.

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

\chapter{The Lesser GPL}

As we have seen in our consideration of the GPL, its text is specifically

designed to cover all possible derivative works under copyright law. Our

goal in designing GPL was to make sure that any derivative work of GPL'd

software was itself released under GPL when distributed. Reaching as far

as copyright law will allow is the most direct way to reach that goal.

However, while the strategic goal is to bring as much Free Software

into the world as possible, particular tactical considerations

regarding software freedom dictate different means. Extending the

copyleft effect as far as copyright law allows is not always the most

prudent course in reaching the goal. In particular situations, even

those of us with the goal of building a world where all published

software is Free Software realize that full copyleft does not best

serve us. The GNU Lesser General Public License (``GNU LGPL'') was

designed as a solution for such situations.

\section{The First LGPL'd Program}

The first example that FSF encountered where such altered tactics were

needed was when work began on the GNU C Library. The GNU C Library would

become (and today, now is) a drop-in replacement for existing C libraries.

On a Unix-like operating system, C is the lingua franca and the C library

is an essential component for all programs. It is extremely difficult to

construct a program that will run with ease on a Unix-like operating

system without making use of services provided by the C library --- even

if the program is written in a language other than C\@. Effectively, all

user application programs that run on any modern Unix-like system must

make use of the C library.

By the time work began on the GNU implementation of the C libraries, there

were already many C libraries in existence from a variety of vendors.

Every proprietary Unix vendor had one, and many third parties produced

smaller versions for special purpose use. However, our goal was to create

a C library that would provide equivalent functionality to these other C

libraries on a Free Software operating system (which in fact happens today

on modern GNU/Linux systems, which all use the GNU C Library).

Unlike existing GNU application software, however, the licensing

implications of releasing the GNU C Library (``glibc'') under GPL were

somewhat different. Applications released under GPL would never

themselves become part of proprietary software. However, if glibc were

released under GPL, it would require that any application distributed for

the GNU/Linux platform be released under GPL\@.

Since all applications on a Unix-like system depend on the C library, it