+autoconf - at least the version specified near the start of
+ configure.in (in the AC_PREREQ command).
+automake - we recommend at least version 1.11.
+makeinfo - not strictly necessary, but highly recommended, so that
+ you can build the manuals.
+
+The `autogen.sh' script can help you figure out if you have the
+necessary tools.
+
+The first time you build, there are a couple of extra steps.
+First, generate the `configure' script and some related files:
+
+ $ ./autogen.sh