\label{gpl-compliance-guide}

The GPLv2 was released two and a half years after GPLv1, and over the

following sixteen years, it became the standard for copyleft licensing until

the release of GPLv3 in 2007 (discussed in more detail in the next section).

While this tutorial does not discuss the terms of GPLv1 in detail, it is

worth noting below the three key changes that GPLv2 brought:

\begin{itemize}

\item Software patents and their danger are explicitly mentioned, inspiring

  (in part) the addition of GPLv2\S\S5--7.  (These sections are discussed in

  detail in \S~\ref{GPLv2s5}, \S~\ref{GPLv2s6} and \S~\ref{GPLv2s7} of this

  tutorial.)

\item GPLv2\S2's copyleft terms are expanded to more explicitly discuss the

  issue of combined works.  (GPLv2\S2 is discussed in detail in

  \S~\ref{GPLv2s2} in this tutorial).

\item GPLv2\S3 includes more detailed requirements, including the phrase

 ``the scripts used to control compilation and installation of the

  executable'', which is a central component of current GPLv2 enforcement

  .  (GPLv2\S3 is discussed in detail in

  \S~\ref{GPLv2s3} in this tutorial).

\end{itemize}

The next chapter discusses GPLv2 in full detail, and readers who wish to dive

into the section-by-section discussion of the GPL should jump ahead now to

that chapter.  However, the most interesting fact to note here is how GPLv2

was published with little fanfare and limited commentary.  This contrasts

greatly with the creation of GPLv3.