Install Apache2 and PHP5 in Debian Etch

Install Apache2:
# apt-get install apache2

Install PHP5 support for Apache2:
# apt-get install libapache2-mod-php5 php5-cli php5-common php5-cgi


References:
Install and Configure Apache2 with PHP5 and SSL Support in Debian Etch
http://www.debianadmin.com/install-and-configure-apache2-with-php5-and-ssl-support-in-debian-etch.html

Configuring Apache 2 on Debian, Ubuntu
http://www.control-escape.com/web/configuring-apache2-debian.html