PHP, which stands for PHP – Hypertext Preprocessor, is an open source HTML-embedded scripting language that is generally used for websites on the Internet. Its main purpose is to allow rapid programming of dynamically generated and interactive web pages.

PHP 5 is the current version of the language with its main improvements in the areas of object-oriented programming. All versions of PHP newer than version 2 are currently supported and in use.

PHP code is typically integrated into an existing web page through the use of code delimiters in a similar way to ASP, ASP.NET, or Ruby. Unlike JavaScript, which runs inside a browser, PHP code is interpreted on the server, generating HTML that is sent to the client’s browser for processing. One of the benefits of the language is its ease of use for newer developers, while retaining a robust list of advanced features for more experienced programmers to exploit.

While primarily used for website programming, PHP can also be used as a command line scripting language suitable for simple word processing tasks. It can also be used to develop desktop applications with a graphical interface using the PHP-GTK library extension, but this is not the best use for PHP compared to other languages ​​designed for GUI development.

A big advantage of PHP is its neutrality towards operating systems and web server software. It works on all major operating system platforms and is compatible with most major web servers, including Microsoft’s Apache and IIS. Another major feature is PHP’s ubiquitous database support that includes large proprietary systems like Oracle and open source options like mySQL.

The success of PHP is an excellent statement about the quality of open source initiatives in a world of largely proprietary software development.

Dynamic content can be anything from a simple GIF image to a fully customized web page rich in features ranging from basic HTML to graphic-intensive interactive Flash. There are other more creative uses as well, but it would be nearly impossible to name them all given the remarkable flexibility of PHP.

Given the extensibility of the language, it is difficult to go into detail about all the functions, since there are probably thousands of them that replace the 100 or so basic functions. However, PHP shares syntax with most common high-level languages, such as blocks for ‘if’ conditions and ‘for’ and ‘while’ loops. As with C/C++, variable names are case sensitive and, with a few exceptions, variables must be declared before they are used, as well as specified in the type. The variable types available in PHP are remarkably similar to those found in C/C++ and Java.

Modern versions of PHP are object oriented just like modern versions of C/C++. In fact, PHP’s relationship with the C programming language is now so close that it is possible for developers to write C extensions to add additional functionality to the PHP language.

Lastly, integrated event handling is not limited to just predictable behavior. PHP has since its inception as a public project a great ability to handle errors, which is mission critical. Who wants an unexpected event to crash an entire site or even just one aspect like eCommerce?