source code, or it may be accompanied by a written offer to provide the

machine-readable source code to any third party. GPLv3 clarifies that the

medium for software interchange on which the machine-readable source code is

provided must be a durable physical medium. Subsection 6b does not prevent a

distributor from offering to provide source code to a third party by some

other means, such as transmission over a network, so long as the option of

obtaining source code on a physical medium is presented.

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

Subsection 6b revises the requirements for the written offer to provide

source code. As before, the offer must remain valid for at least three

years. In addition, even after three years, a distributor of a product

containing GPL'd object code must offer to provide source code for as long as

the distributor also continues to offer spare parts or customer support for

the product model. We believe that this is a reasonable and appropriate

requirement; a distributor should be prepared to provide source code if he or

she is prepared to provide support for other aspects of a physical product.

% FIXME: 10x language is gone.

Subsection 6b also increases the maximum permitted price for providing a copy

of the source code. GPLv2 stated that the price could be no more than the

cost of physically performing source distribution; GPLv3 allows the price to

be up to ten times the distributor's cost. It may not be practical to expect

some organizations to provide such copies at cost. Moreover, permitting such

organizations to charge ten times the cost is not particularly harmful, since

some recipient of the code can be expected to make the code freely available

on a public network server. We also recognize that there is nothing wrong

with profiting from providing copies of source code, provided that the price

of a copy is not so unreasonably high as to make it effectively unavailable.

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

Subsection 6c gives narrower permission than the corresponding subsection in

GPLv2.  The option of including a copy of an offer received in accordance

with subsection 6b is available only for private distribution of object code;

moreover, such private distribution is restricted to ``occasional

non-commercial distribution.''  This subsection makes clear that a

distributor cannot comply with the GPL merely by making object code available

on a publicly-accessible network server accompanied by a copy of the written

offer to provide source code received from an upstream distributor.

% 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: publicly documented format

\section{Understanding License Compatibility}

\label{license-compatibility}

\section{GPLv3~\S7: Explicit Compatibility}

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

In GPLv3 we take a new approach to the issue of combining GPL'd code with

code governed by the terms of other free software licenses. Our view, though

it was not explicitly stated in GPLv2 itself, was that GPLv2 allowed such

combinations only if the non-GPL licensing terms permitted distribution under

the GPL and imposed no restrictions on the code that were not also imposed by

the GPL. In practice, we supplemented this policy with a structure of

exceptions for certain kinds of combinations.

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

Section 7 of GPLv3 implements a more explicit policy on license

compatibility. It formalizes the circumstances under which a licensee may

release a covered work that includes an added part carrying non-GPL terms. We

distinguish between terms that provide additional permissions, and terms that

place additional requirements on the code, relative to the permissions and

requirements established by applying the GPL to the code.

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

Section 7 first explicitly allows added parts covered by terms with

additional permissions to be combined with GPL'd code. This codifies our

existing practice of regarding such licensing terms as compatible with the

GPL. A downstream user of a combined GPL'd work who modifies such an added

part may remove the additional permissions, in which case the broader

permissions no longer apply to the modified version, and only the terms of

the GPL apply to it.

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

In its treatment of terms that impose additional requirements, section 7

extends the range of licensing terms with which the GPL is compatible. An

added part carrying additional requirements may be combined with GPL'd code,

but only if those requirements belong to an set enumerated in section 7. We

must, of course, place some limit on the kinds of additional requirements

that we will accept, to ensure that enhanced license compatibility does not

defeat the broader freedoms advanced by the GPL. Unlike terms that grant

additional permissions, terms that impose additional requirements cannot be

removed by a downstream user of the combined GPL'd work, because no such user

would have the right to do so.

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

Under subsections 7a and 7b, the requirements may include preservation of

copyright notices, information about the origins of the code or alterations

of the code, and different warranty disclaimers. Under subsection 7c, the

requirements may include limitations on the use of names of contributors and

on the use of trademarks for publicity purposes. In general, we permit these

requirements in added terms because many free software licenses include them

and we consider them to be unobjectionable. Because we support trademark fair

use, the limitations on the use of trademarks may seek to enforce only what

is required by trademark law, and may not prohibit what would constitute fair

use.

% FIXME: 7d-f

% FIXME:  removing additional restrictions

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

Section 7 requires a downstream user of a covered work to preserve the

non-GPL terms covering the added parts just as they must preserve the GPL, as

long as any substantial portion of those parts is present in the user's

version.

\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