Elegance and power has made PHP a top scripting language.
What is it?
PHP stands for PHP: Hypertext Preprocessor. It is an HTML-embedded scripting language which enables web developers to write dynamically generated pages quickly.
PHP comes from the Apache stable, but internet research site Netcraft has reported PHP becoming increasingly popular with Microsoft users.
The May 2002 Netcraft Survey found PHP and Microsoft's Active Server Pages running neck and neck as the most favoured server-side scripting languages, with about 24% of the market each.
Where did it originate?
PHP was created in 1994 by Rasmus Lerdorf, a programmer from Greenland, who called it Personal Home Page tools. In 1997 it was completely rewritten by Andi Gutmans and Zeev Suraski. With Lerdorf's co-operation, this commercially robust version was released as PHP3.
The most widely used version, PHP4, introduced the "engine" supplied by PHP specialist Zend. This delivered improved modularity, support for a wider range of databases and better performance.
What is it for?
PHP is used mainly for server-side scripting. Originally devised as a forms interpreter (it used to be called PHP/FI), PHP can collect data from web page users or retrieve and modify data in databases and on other web pages. It can also be used for command-line scripting and even for desktop applications.
What makes it special?
According to Zend, PHP incorporates, "C's elegant syntax without the hassle of memory and pointer management, as well as Perl's powerful performance without the complexity often associated with Perl scripts". It contains a lot of pre-built functionality to make life easier for developers.
PHP5, released this summer, finally offers decent object-oriented programming support, better integration with the MySQL database with which it is most often used, its own embedded database (SQLite), full support for Soap and a suite of XML tools.
How difficult is it to master?
Developers with a working knowledge of HTML and either C, Java or Perl should pick it up easily. For beginners it is easier to learn than any of these languages, and it is often favoured by sites with no full-time IT staff. As an alternative to Zend Studio, there is the Nusphere PHPED integrated development environment.
Where is it used?
Based on Netcraft data, Zend said there are nearly two million unique IP addresses residing on servers "where PHP is supported and used". How much use they make of it is impossible to establish.
Zend said it has 4,000 customers, including Hewlett-Packard, Nortel Networks, Sprint, Wall Street Online, Boeing, Lufthansa and Disney.
What systems does it run on?
Linux and Unix variants including HP-UX, Solaris, OpenBSD, Windows, Mac OS X, Apache, Microsoft IIS and Netscape.
Not many people know that...
PHP is part of the Lamp (Linux, Apache, MySQL,Perl/Python/PHP) platform.
What is coming up?
With PHP5 only just out, there are unlikely to be any changes for a year or two, but there are regular bug-fixes.
Rates of pay
Web developers with PHP can look for £20,000 to £30,000. PHP can also be used alongside C and other languages in application development.
The PHP developer site and Zend both offer tutorials. Zend offers a certification programme linked to a worldwide network of commercial certification testing centres. PHP can be download from these sites:
www.php.net and www.zend.com
This was first published in November 2004