   GNU `m4' is an implementation of the traditional UNIX macro
processor.  It is mostly SVR4 compatible, although it has some
extensions (for example, handling more than 9 positional parameters to
macros).  `m4' also has builtin functions for including files, running
shell commands, doing arithmetic, etc.  Autoconf needs GNU `m4' for
generating `configure' scripts, but not for running them.

   GNU `m4' was originally written by Rene Seindal, with subsequent
changes by Francois Pinard and other volunteers on the Internet.  All
names and email addresses can be found in the file `THANKS' from the
GNU `m4' distribution.

   GNU m4 is now to be considered stable, future
releases are only meant to fix bugs, increase speed, or improve
documentation.  However...

   An experimental feature, which would improve `m4' usefulness, allows
for changing the syntax for what is a "word" in `m4'.  You should use:
     ./configure --enable-changeword

if you want this feature compiled in.  The current implementation slows
down `m4' considerably and is hardly acceptable.  So, it might go away,
do not count on it yet.

WWW: http://www.gnu.org/software/m4/
