Prepare your Ubuntu server (you are required to be a sudoer)

$ sudo apt-get update
$ sudo apt-get upgrade
$ sudo apt-get install apache2 libapache2-mod-php5 php5-pgsql git-core

Install Agorae

$ cd /var/www/
$ sudo git clone git://agorae.git.sourceforge.net/gitroot/agorae/agorae
$ cd agorae/library
$ sudo tar xvzf zend.tar.gz 
$ cd ../application/config
$ sudo cp ucadao.hypertopic.org.ini yourserver.acme.com.ini

Edit your config file

...

Edit the virtual host configuration file

ServerName agorae.foo.bar
DocumentRoot /var/www/agorae/public
<Directory /var/www/agorae/public/>
   AllowOverride FileInfo
...

$ sudo /etc/init.d/apache2 force-reload