Since Apache is most of the time a memory hungy process, people started to look for different ways to host their website.
Apache is clearly not the only webserver available. A few good examples are lighttpd and nginx. In this tutorial I will show you how to install it on your Ubuntu server. This tutorial also applies to Debian, though. There is only a very small difference. Ready? Let's begin shall we.
http://howtoforge.com/installing-php-5.3-nginx-and-php-fpm-on-ubuntu-debian