PHP acts primarily as a filter,[86] taking input from a file or stream containing text and/or PHP instructions and outputting another stream of data; most commonly the output will be HTML, although it could be JSON, XML or image data, among others useful in web development. Since PHP 4, the PHP parser compiles input to produce bytecode for processing by the Zend Engine, giving improved performance over its interpreter predecessor.[87]
Originally designed to create dynamic web pages, PHP now focuses mainly on server-side scripting,[88] and it is similar to other server-side scripting languages that provide dynamic content from a web server to a client, such as Microsoft's ASP.NET, Sun Microsystems' JavaServer Pages,[89] and mod_perl. PHP has also attracted the development of many software frameworks that provide building blocks and a design structure to promote rapid application development (RAD). Some of these include PRADO, CakePHP, Symfony, CodeIgniter, Laravel, Yii Framework, and Zend Framework, offering features similar to other web application frameworks.
The LAMP architecture has become popular in the web industry as a way of deploying web applications. PHP is