PHP is a web scripting language that performs server side operations to produce dynamic content.

The PHP code can be embedded into conventional HTML performing many tasks that were formerly mostly relayed to a separate Common Gateway Interface (CGI) script. Created by Rasmus Lerdorf originally in the form of Perl-based CGI binary files, PHP has become one of the most widely-used scripting languages for the web.

The script, written in C, reads very much like Perl and can be described as a Perl-like script that can be embedded into HTML to perform server operations with databases, log files, user agents and the like. The developer is The PHP Group and the latest version is PHP 5.2.10 on 06-18-2009. There are also unstable releases: 5.3.0RC4 and 6.0.0-dev.

PHP is freeware under the PHP license rather than the GNU General Public License. The scripting language works across operating systems and on both 32 bit and 64 bit platforms, although the 32 bit is the only official one for Windows.

The name "PHP" comes from the original "Personal Home Page Tools" coined by Lerdorf. The language, like Perl, can also be used to create command-line scripts and client-side interface scripts.

For those who already know HTML, and Perl, PHP is very easy to learn. In some ways PHP is similar to embedding Javascript into an HTML page, except that PHP runs on the server rather than in the client browser. PHP shares Perl’s powerful parsing ability and is great for handling user input. The scripting language is normally compiled at runtime, but can be compiled into binary form before hand for maximum speed. Developers should be careful in not using too many resources with each script since it is easy to overload the server. PHP has some significant security issues and lacks taint checking like Perl for external input.

PHP scripts are placed in HTML set off by delimiters. The language has a wide range of functions and PHP 3 upward have object-oriented capability.

PHP has become one of the most popular active server pages and is supported by an active developer community.