Comment 2 for bug 1405424

This solves:

From: http://askubuntu.com/questions/368515/upgraded-to-ubuntu-13-10-apache-not-able-to-start

sudo apt-get install apache2-prefork-dev libxml2 libxml2-dev
mkdir ~/modbuild/ && cd ~/modbuild/
wget http://apache.webthing.com/svn/apache/filters/mod_xml2enc.c
wget http://apache.webthing.com/svn/apache/filters/mod_xml2enc.h
sudo apxs2 -aic -I/usr/include/libxml2 ./mod_xml2enc.c
cd ~
rm -rfd ~/modbuild/
sudo service apache2 restart