PHP is a widely-used general-purpose scripting language that is especially suited for Web development and can be embedded into HTML. Much of its syntax is borrowed from C, Java and Perl with a couple of unique PHP-specific features thrown in. The goal of the language is to allow web developers to write dynamically generated pages quickly. It is a project of the Apache Software Foundation.
Changes:
PHP 5 features the Zend Engine 2
XML support has been completely redone in PHP 5, all extensions are now focused
around the excellent libxml2 library
SQLite has been bundled with PHP
Streams have been greatly improved, including the ability to access low-level