<sect2><title>Contents of M4</title>

<!-- <para>(Last checked against version &m4-contversion;.)</para> -->

<para>M4 is a macro processor. It copies input to output, expanding
macros as it goes. Macros are either built-in or user-defined and can
take any number of arguments. Besides just doing macro expansion, m4
has built-in functions for including named files, running Unix
commands, doing integer arithmetic, manipulating text in various ways,
recursion, etc. The m4 program can be used either as a front-end to a
compiler or as a macro processor in its own right.</para>

<para><emphasis>Installed program</emphasis>: m4</para>

</sect2>
