Installing on Debian Etch
From OpenCms Wiki
Installing the necessary software
apt-get update apt-get install sun-java5-jdk sun-java5-jre update-alternatives --config java update-alternatives --config javac apt-get install tomcat5.5 tomcat5.5-admin tomcat5.5-webapps
In case you want to run an ordinary Apache as a proxy in front of Tomcat, also install the mod-jk package:
apt-get install libapache2-mod-jk