A HOWTO on Optimizing PHP

PHP is a very fast programming language, but there is more to optimizing PHP than just speed of code execution. This article explains why optimizing PHP involves many factors which are not code related, and why tuning PHP requires an understanding of how PHP performs in relation to all the other subsystems on your server, and then identifying bottlenecks caused by these subsystems and fixing them. It also covers how to tune and optimize your PHP scripts so they run even faster.