How to create a more optimised PHP script, at the language level.
We're going to talk about methods and rumors we've heard about how to create high performance PHP scripts. The scope of this is in the PHP language/module and the core (or PECL/PEAR) functionality. Of course, additional steps should be taken to ensure the performance of your Lighttpd, Apache, MySQL, PostgreSQL, CouchDB or what-ever else your environment depents on.
Much of this information is covered elsewhere on the internet.