+- Automake <http://www.gnu.org/software/automake/>
+- Autoconf <http://www.gnu.org/software/autoconf/>
+- Bison <http://www.gnu.org/software/bison/>
+- Gettext <http://www.gnu.org/software/gettext/>
+- Gzip <http://www.gnu.org/software/gzip/>
+- M4 <http://www.gnu.org/software/m4/>
+- Texinfo <http://www.gnu.org/software/texinfo>
+- Wget <http://www.gnu.org/software/wget/>