What Is PHP?

Let's break down the term PHP. PHP stands for Hypertext Preprocessor.

What this all means is that PHP takes hypertext, or the text that is used online such that includes links, etc., and performs different actions to that information before it reaches your browser in order to correctly display it to the user.

The PHP Group, the group responsible for creating and maintaining the PHP language, defines PHP as "a widely-used general-purpose scripting language that is especially suited for Web development and can be embedded into HTML." In most cases, PHP is used as a server-side scripting language being utilized in correlation with HTML in order to create a better web experience. This means that the server, or the computer used to send the information to the browser, processes different information and sends it to the browser differently depending on the conditions. This allows for static parts of a page using HTML to be integrated with dynamic parts of the page using PHP.

Why Use PHP?

So now you have an idea what PHP is, but why would you ever use PHP? Well, PHP offers something that a simple site that uses only HTML does not, and can not offer. It offers the ability to be dynamic and ever changing. This is the main idea behind a server-side scripting language. It preprocesses information before it is sent to a user's browser, allowing the server to make decisions on what type of information needs to be displayed. This type of ability opens the door for content management systems, used on sites like PSU's Angel, and e-commerce solutions, such as a shopping cart used on sites like Amazon, that would be extremely difficult, if not impossible, using pure HTML.

There is also another very large benefit to using PHP. PHP is currently open source, which is defined by the Open Source Initiative as "a development method for software that harnesses the power of distributed peer review and transparency of process." In lamens terms, this means that PHP's source code is available for anyone to edit or enhance at any time. This allows for large groups of talented developers to collaborate on the project and not only keep it going but to have a large system of checks and balances to make sure it works correctly. Using an open source method also allows for developers to add features, so if one day you want to be able to do something with the language, all you have to do is add that component to the source code and every PHP developer will be able to use it.

Comparison

In Figure 1, you can clearly see how popular PHP is in comparison to other programming languages as well as some simpler languages such as HTML. Figure 1 displays the amount of commits per month using HTML, PHP, Ruby, and Python. A commit is when a developer changes the code of a particular project and then "commits" that change into a versioning system. This type of system is used in almost every major programming project. It is used to keep large, collaborative projects in sync as well as document any changes that may have occurred over time. PHP is clearly the front runner in server side scripting languages (PHP, Ruby, and Python) and even keeps up with HTML which is used in almost every web project.

Monthly Statistics
Figure 1: Amount of Monthly Commits Per Month From 2000 to Early 2009
Source: ohloh:Root
History of PHP

The history of PHP is the story of an ever-growing language that is constantly evolving to keep with the standard technological needs of the community. The first version of PHP was actually called PHP/FI and was created in 1995 by a man named Ramsus Lerdorf. PHP began as a series of Perl scripts and evolved into a more complex version of those scripts written in C. It was originally only built to access Ramsus Lerdorf's online resume, but soon needed added functionality to compete. It was not until 1998 that a group of developers came together and made the PHP engine. This engine consisted of all the functionality that had come from the first two versions of PHP/FI as well as added functionality to keep the language growing. By the end of 1998, PHP had a strong backing from the community and continued you grow. PHP's current version, released on September 17, 2009, is PHP 5.2.11. The major version release history for PHP is as follows:

PHP has slowly been growing over the past 15 years and has become one of the largest and most widely used open-source scripting language on the Web. PHP 4 has recently begun to fade out as The PHP Group has been building PHP 6 and it is nearing release. This type of growth has shown that PHP is ever-changing and has a large community of developers behind it to keep it constantly moving for over 15 years. PHP has been able to keep up with all major changes on the web and has continually grown in popularity. Now is the time to join in on the experience and take your development skills to the next level using PHP!

Sources