 usage of php php is a generalpurpose scripting language that is especially suited for web development  it is the fourth most popular computer programming language ranking behind java   c  and visual basic   23  php generally runs on a web server  taking php code as its input and creating web pages as output it can also be used for commandline scripting and clientside gui applications php can be deployed on most web servers  many operating systems and platforms  and can be used with many relational database management systems  it is available free of charge and the php group provides the complete source code for users to build customize and extend for their own use  5  php primarily acts as a filter  24   taking input from a file or stream containing text and or php instructions and outputs another stream of data most commonly the output will be html from php 4 the php parser compiles input to produce bytecode for processing by the zend engine  giving improved performance over its interpreter predecessor  25  originally designed to create dynamic web pages php s principal focus is serverside scripting  26   and it is similar to other serverside scripting languages that provide dynamic content from a web server to a client  such as microsoft  s aspnet system  sun microsystems   javaserver pages  27   and modperl  php has also attracted the development of many frameworks that provide building blocks and a design structure to promote rapid application development  rad some of these include cakephp   prado   symfony 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 commonly used as the p in this bundle alongside linux   apache and mysql  although the p can also refer to python or perl  as of april 2007 over 20 million internet domains were hosted on servers with php installed and php was recorded as the most popular apache module  6  