\section{GPLv3~\S5: Modified Source}

\label{GPLv3s5}

GPLv3\S5 is the rewrite of GPLv2\S2, which was discussed in \S~\ref{GPLv2s2}

of this tutorial.  This section discusses the changes found in GPLv3\S5

compared to GPLv2\S2.

GPLv3\S5(a) still requires modified versions be marked with ``relevant

date'', but no longer says ``the date of any change''.  The best practice is

to include the date of the latest and/or most significant changes and who

made those.  Of course, compared to its GPLv2\S2(a), GPLv3\S5(a) 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.

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.

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: 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.