PHP is a general-purpose server-side scripting language originally designed for web development to produce dynamic web pages. PHP code is embedded into the HTML source document and interpreted by a web server with a PHP processor module, which generates the web page document. It also has evolved to include a command-line interface capability and can be used in standalone graphical applications. PHP can be deployed on most web servers and as a standalone interpreter, on almost every operating system and platform free of charge. There is also commercial software such as RadPHP, a rapid application development framework for the PHP language. PHP is installed on more than 20 million websites and 1 million web servers.
What Is Open Source?
PHP, Apache, and MySQL are all part of the open source group of software programs. The open source movement is basically a collaboration of some of the finest minds in computer programming. By allowing the open exchange of information, programmers from all over the world contribute to make a truly powerful and efficient piece of software available to everyone. Through the contributions of many people to the publicly available source code, bugs get fixed, improvements are made, and a “good” software program becomes a “great” one over time.
PHP is a server-side scripting language that allows your Web site to be truly dynamic. PHP stands for PHP: Hypertext Preprocessor (and, yes, we’re aware PHP is a “recursive acronym”—probably meant to confuse the masses). Its flexibility and relatively small learning curve (especially for programmers who have a background in C, Java, or Perl) make it one of the most popular scripting languages around. PHP’s popularity continues to increase as businesses and individuals everywhere embrace it as an alternative to Microsoft’s ASP language and realize that PHP’s benefits most certainly outweigh the costs (three cheers for open source!). According to Zend Technologies, Ltd., the central source of PHP improvements and designers of the Zend Engine, which supports PHP applications, PHP code can now be found in approximately 9 million Web sites.
PHP was originally created by Rasmus Lerdorf in 1995. The main implementation of PHP is now produced by The PHP Group. PHP is free software released under the PHP License which is incompatible with the GNU General Public License (GPL) due to restrictions on the usage of the term PHP.
With the development of PHP5, Zend brings some new methodologies to the PHP table. The biggest change to note is the switch in focus from procedural programming to OOP (object oriented programming). While procedural programming has served PHP well thus far, large and complex programs are much better served with OOP. Currently, PHP4 passes variables by value instead of reference. PHP5 changes all that. The new PHP5 provides for improved error handling and integration of objects from external sources, such as Java.