PHP is an open-source, reflective programming language. Originally designed as a high-level tool for producing dynamic web content, PHP is used mainly in server-side applications.

PHP has a formal development manual that is maintained by the open source community. In addition, answers to most questions can often be found by doing a simple internet search. PHP users assist each other through various media such as chat, forums, newsgroups and PHP developer web sites. In turn, the PHP development team actively participates in such communities, garnering assistance from them in their own development effort (PHP itself) and providing assistance to them as well. There are many help resources available for the novice PHP programmer.
When running server-side, the PHP model can be seen as an alternative to Microsoft’s ASP.NET/C#/VB.NET system, Macromedia’s ColdFusion, Sun Microsystems’ JSP, Zope, mod_perl and the Ruby on Rails framework.

The LAMP architecture has become popular in the Web industry as a way of deploying inexpensive, reliable, scalable, secure web applications. PHP is commonly used as the P in this bundle alongside Linux, Apache and MySQL. PHP can be used with a large number of relational database management systems, runs on all of the most popular web servers and is available for many different operating systems. This flexibility means that PHP has a wide installation base across the Internet.

More recently, PHP has been adapted to provide a command line interface, as well as GUI libraries such as GTK+ and text mode libraries like Ncurses and Newt in order to facilitate development of a broader range of software.