PHP

PHP is a widely-used open source general-purpose scripting language that is especially suited for web development and can be embedded into HTML. In order to run a PHP script, you need a Web server that has PHP installed. The most popular Web server for PHP is Apache. When a visitor opens a PHP page, the Web server executes the PHP code and then sends the output (HTML code) to the visitor's Web browser. PHP scripts can generate dynamic Web page content. They can also be used to interact with databases, such as MySQL. PHP is free to download and use.