What is it?
PHP is an HTML-embedded scripting language, used mainly for
server-side scripting. The abbreviation originally stood for
"Personal Home Page" but it is now recognised to be "PHP: Hypertext
Processor".
PHP is one of the Ps in the Lamp (Linux/Apache/MySQL) stack,
with Perl and Python as alternatives.
From the outset its main purpose has been to enable developers
to create dynamic web pages quickly. PHP is open source, free
software, with a supportive community and a great deal of free
training material.
After a year of moderate decline, PHP usage has resumed its
growth, according to the monthly Netcraft survey of internet
trends.
The Tiobe Community Programming Index currently places it fifth
after Java, C and C++, and Visual Basic in terms of worldwide
availability of skilled engineers, courses and third-party
suppliers.
Evans Data Corporation suggests that in the US it is one of the
languages ousting Visual Basic as the focus for development moves
from the desktop to the web.
Where did it originate?
PHP was created in 1994 by Rasmus Lerdorf, who wanted to display
his CV and track visits on his personal home page. On release in
1995, it also included Lerdorf's Forms Interpreter, and was called
PHP/FI.
Zeev Suraski and Andi Gutmans created what became known as the
Zend Engine, and later founded Zend Technologies, which maintains
the language. PHP 5, with Zend Engine II, was released in 2004,
adding greater support for object orientation, MySQL and Simple
Object Access Protocol, among other enhancements. PHP 4 is still
going strong.
What's it for?
According to Security Space's monthly internet reports, PHP is
the most popular add-on module to the Apache web server, used by
more than 40% of Apache sites.
By contrast, Perl is used at 9.5% of Apache sites and Python at
just under 2%. As well as server-side scripting, PHP is used for
command line scripting, and even for desktop applications.
What makes it special?
PHP's supporters claim it has C's elegant syntax and Perl's
powerful performance, without the complexity of either.
How difficult is it to master?
You will need a working knowledge of HTML, and a background in
C, Perl or Java is helpful, though for beginners it is easier than
any of these.
Where is it used?
PHP users include Hewlett-Packard, Nortel Networks, Boeing,
Lufthansa and Disney. It is shipped and supported along with most
Linux distributions. It is also favoured by organisations with
small budgets and no full-time IT staff.
What systems does it run on?
Every web server (but especially Apache) and most operating
systems.
What's coming up?
PHP 6 is already in development, with a specification based on
users' responses to PHP 5. Some gaps, such as native Unicode
support, will be filled. The Zend Framework, a collection of
building blocks and best practices, is being put together to make
PHP more competitive with the likes of ASP.net.
Training
Start with the following websites:
www.php.org
www.php.net
devzone.zend.com
There are plenty of others, especially if you combine your
search with other elements of the Lamp stack, such as MySQL.
O'Reilly's ONLamp is a good source. For more formal training, and
certification management see:
www.zend.com
Rates of pay
Developers who combine PHP with other web skills can look for a
salary of £30,000 and upwards.
Catch up with hot skills
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