GPLv3\S5(b) is a new but simple provision. GPLv3\S5(b)  requires that the

license text itself must be unmodified (except as permitted by GPLv3\S7; see

\S~\ref{GPLv3s7} in this tutorial).  Furthermore, it  removes any perceived

conflict between the words ``keep intact all notices'' in GPLv3\S4, since

operating under GPLv3\S5 still includes all the requirements of GPLv3\S4 by

reference.

GPLv3\S5(c) is the primary source-code-related copyleft provision of GPL. (The

object-code-related copyleft provisions are in GPLv3\S6, discussed in

\S~\ref{GPLv3s6} of this tutorial).  Compared to GPLv2\S2(b), GPLv3\S5(c)

states that the GPL applies to the whole of the work.  Such was stated

already in GPLv2\S2(b), in ``in whole or in part'', but this simplified

wording makes it clear the entire covered work

Another change in GPLv3\S5(c) is the removal of the

words ``at no charge,'' which was often is misunderstood upon na\"{i}ve

reading of in GPLv2\S(b) (as discussed in \S~\ref{GPLv2s2-at-no-charge} of this

tutorial).

%  FIXME-LATER: Write up something on 5d, and related it to Appropriate Legal Notices.

Note that of GPLv2~\S2's penultimate and ante-penultimate paragraphs are now

handled adequately by the definitions in GPLv3\S0 and as such, have no direct

analogs in GPLv3.

GPLv2~\S2's final paragraph, however, is reworded and expanded into the final

paragraph of GPLv3\S5, which now also covers issues related to copyright

compilations (but not compilations into object code --- that's in the next

section!).  The intent and scope is the same as was intended in GPLv2.

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

\label{GPLv3s6}

GPLv3~\S6 clarifies and revises GPLv2~\S3.  It requires distributors of GPL'd

object code to provide access to the corresponding source code, in one of

four specified ways.  As noted in \S~\ref{GPLv3s0}, ``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.

GPLv3~\S6(a--b) now apply specifically to distribution of object code in a

physical product.  Physical products include embedded systems, as well as

physical software distribution media such as CDs.  As in GPLv2~\S3 (discussed

in \S~\ref{GPLv2s3} of this tutorial), the distribution of object code may

either be accompanied by the machine-readable source code, or it may be

accompanied by a valid written offer to provide the machine-readable source

code.  However, unlike in GPLv2, that offer cannot be exercised by any third

the offer.  (Note that this is a substantial narrowing of requirements of

offer fulfillment, and is a wonderful counterexample to dispute claims that

the GPLv3 has more requirements than GPLv2.)

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

GPLv3~\S6(b) further 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.  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.

GPLv3~\S6(a--b) clarifies that the medium for software interchange on which

the machine-readable source code is provided must be a durable physical

medium.  GPLv3~\S6(b)(2), however, permits a distributor to instead offer to

provide source code from a network server instead, which is yet another

example GPLv3 looser in its requirements than GPLv2 (see

\S~\ref{GPLv2s3-medium-customarily} for details).

% FIXME-LATER: more information about source provision, cost of physically

% performing, reasonable fees, medium customary clearly being said durable

% connecting back to previous text

GPLv3\S6(c) gives narrower permission than GPLv2\S3(c).  The ``pass along''

option for GPLv3\S6(c)(1) offers is now available only for individual

distribution of object code; moreover, such individual distribution can occur

only ``occasionally and noncommercially.''  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-LATER: tie back to the discussion of the occasional offer pass along

%             stuff in GPLv2 this tutorial.

GPLv3~\S6(d) revises and improves GPLv2~\S3's final paragraph.  When object

code is provided by offering access to copy the code from a designated place

(such as by enabling electronic access to a network server), the distributor

must merely offer equivalent access to copy the source code ``in the same way

through the same place''.  This wording also 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

its CCS are publicly available at no charge under subsection GPLv3~\S6(d).

The CCS therefore need not be provided through the peer-to-peer system that

was used for providing the binary.

Second, GPLv3\S9 also clarifies that ancillary propagation of a covered work

that occurs as part of the process of peer-to-peer file transmission does not

require acceptance, just as mere receipt and execution of the Program does

not require acceptance.  Such ancillary propagation is permitted without

limitation or further obligation.

% FIXME-LATER: Would be nice to explain much more about interactions between

% the various options of GPLv3~\S6(a-e), which might all be in play at once!

\subsection{User Products, Installation Information and Device Lock-Down}

As discussed in \S~\ref{GPLv3-drm} of this tutorial, GPLv3 seeks thwart

technical measures such as signature checks in hardware to prevent

modification of GPL'd software on a device.

To address this issue, GPLv3~\S6 requires that parties distributing object

code provide recipients with the source code through certain means.  When

those distributors pass on the CCS, they are also required to pass on any

information or data necessary to install modified software on the particular

device that included it.  (This strategy is not unlike that used in LGPLv2.1

to enable users to link proprietary programs to modified libraries.)

% FIXME-LATER: LGPLv2.1 section should talk about this explicitly and this

%              should be a forward reference here

\subsubsection{User Products}

\label{user-product}

The scope of these requirements are narrow.  GPLv3~\S6 introduces the concept

of a ``User Product'', which includes devices that are sold for personal,

family, or household use.  Distributors are only required to provide

Installation Information when they convey object code in a User Product.

In brief, the right to convey object code in a defined class of ``User

Products,'' under certain circumstances, on providing whatever information is

required to enable a recipient to replace the object code with a functioning

modified version.

This was a compromise that was difficult for the FSF to agree to during the

GPLv3 drafting process.  However, companies and governments that use

specialized or enterprise-level computer facilities reported that they

actually \textit{want} their systems not to be under their own control.

Rather than agreeing to this as a concession, or bowing to pressure, they ask

here, since the main problem lies elsewhere.

While imposing technical barriers to modification is wrong regardless of

circumstances, the areas where restricted devices are of the greatest

practical concern today fall within the User Product definition.  Most, if

not all, technically-restricted devices running GPL-covered programs are

consumer electronics devices.  Moreover, the disparity in clout between the

manufacturers and these users makes it difficult for the users to reject

technical restrictions through their weak and unorganized market power.  Even

limited to User Products, this provision addresses the fundamental problem.

% FIXME-LATER: link \href to USC 2301

The core of the User Product definition is a subdefinition of ``consumer

product'' adapted from the Magnuson-Moss Warranty Act, a federal

consumer protection law in the USA found in 15~USC~\S2301: ``any tangible

personal property which is normally used for personal, family, or household

purposes.''  The USA has had three decades of experience of liberal

judicial and administrative interpretation of this definition in a manner

favorable to consumer rights.\footnote{The Magnuson-Moss consumer product

  definition itself has been influential in the USA and Canada, having been

  adopted in several state and provincial consumer protection laws.}

Ideally, this body of interpretation\footnote{The FSF, however, was very

  clear that incorporation of such legal interpretation was in no way

  intended work as a general choice of USA law for GPLv3.} will guide

interpretation of the consumer product subdefinition in GPLv3~\S6, and this

will hopefully provide a degree of legal certainty advantageous to device

manufacturers and downstream licensees alike.

One well-established interpretive principle under Magnuson-Moss is that

ambiguities are resolved in favor of coverage.  That is, in cases where

it is not clear whether a product falls under the definition of consumer

product, the product will be treated as a consumer product.\footnote{16

CFR~\S\ 700.1(a); \textit{McFadden v.~Dryvit Systems, Inc.}, 54

UCC~Rep.~Serv.2d 934 (D.~Ore.~2004).}  Moreover, for a given product,

``normally used'' is understood to refer to the typical use of that type

of product, rather than a particular use by a particular buyer.

Products that are commonly used for personal as well as commercial

purposes are consumer products, even if the person invoking rights is a

commercial entity intending to use the product for commercial

purposes.\footnote{16 CFR \S \ 700.1(a).  Numerous court decisions

interpreting Magnuson-Moss are in accord; see, e.g., \textit{Stroebner

Motors, Inc.~v.~Automobili Lamborghini S.p.A.}, 459 F.~Supp.2d 1028,

1033 (D.~Hawaii 2006).}  Even a small amount of ``normal'' personal use

is enough to cause an entire product line to be treated as a consumer

product under Magnuson-Moss\footnote{\textit{Tandy Corp.~v.~Marymac

Industries, Inc.}, 213 U.S.P.Q.~702 (S.D.~Tex.~1981). In this case, the

court concluded that TRS-80 microcomputers were consumer products, where