Installing PHP

PHP is currently among the most popular programming languages for the Web. Many of the largest and most popular sites are powered by software written in PHP, including Facebook, Yahoo!, Wikipedia, and Wordpress.com. PHP started as a set of simple tools for designing dynamic personal home pages, but it quickly grew in popularity and evolved into a modern, object-oriented programming language. The open source community that grew around the language created many useful libraries and added support for multiple platforms, databases, and so on.

PHP is quite powerful, yet very easy to use. Deployment of a PHP application usually boils down to placing source code files in a directory on a server. It's also very easy to start programming with PHP—its code can be embedded directly within standard HTML. PHP makes programming for the Web very simple by abstracting away details of the HTTP protocol. For example, form values are available directly as data structures inside scripts, simple...