PHP is a free scripting language running on over 700,000 Web sites, and
PHP's rapid ascent is reflected in its steadfast presence at the top of
oreilly.com's search logs over the past year. An open-source, cross-platform
alternative to Microsoft's Active Server Pages (ASP) technology, PHP scripts
are embedded within a Web page along with HTML.
How exactly do you describe PHP?
It is a server-side HTML-embedded scripting language. It competes with
Microsoft's ASP, and Allaire's ColdFusion, but PHP is completely free and
backed by a large open-source community.
How is it being used currently?
It is being used to create dynamic Web pages. One very popular use is
with the Apache Web server as an Apache module and also with various
databases. PHP lets you build Web front-ends to data stored in database
back-ends without needing to learn a lot of complex programming.
[Editor's note: PHP came in as the top choice on E-Soft's February
Apache Module Report survey.
What's the story behind PHP's creation?
Back in 1995 I created a number of simple scripts to spruce up my personal
Web page a bit. I packaged these tools into a package I called the Personal
Home Page Tools. They were based on a simple cgi wrapper that did
custom-logging and some simple macro replacements in the pages it served
I was then hired by the University of Toronto to help build a dialup system
for the school. They needed a system that would be completely Web-managed
and tie together a student database, Cisco terminal servers, and a
number of other components. I looked around for a good tool to help me do
this and was unable to find one I liked. Instead, I went ahead and rewrote
my PHP Tools package to be a much more general-purpose parsing language
with a set of extensions to make it communicate with a database and other
And from there is has grown significantly. Another complete rewrite lead to
PHP version 3.0, which was based around a parser rewrite by Zeev Suraski
and Andi Gutmans. We are undergoing a complete rewrite for PHP version
4.0, and we see no signs of slowdown in the growth of PHP.
Exactly which version of PHP does this pocket reference cover?
The new features added up to version 3.0.13 are covered in the PHP Pocket
Reference. The chapter I wrote on PHP in O'Reilly's
in a Nutshell covered up to version 3.0.8. A complete list of changes
can be seen at
What new things will PHP 4 address?
PHP 4 includes a complete rewrite of the underlying scripting engine
based on the Zend engine from
Zend Technologies. It
also includes major enhancements to most of the extensions. PHP 4 will be
completely threadsafe and will include support for embedding PHP into more
Web servers. A full list of changes will be available when PHP 4 is released
later this year. Beta
versions are currently available. I'm also working on a book that
will cover PHP 4.
E-Soft survey indicates that PHP is now the most
popular Apache module. Why is PHP generating so much interest?
I think it is mostly because the barrier of entry to PHP development is
low. It doesn't take a lot of prior experience to create interesting dynamic
Web pages with PHP. It is also free and bundled with all the popular free
Unix distributions, so a lot of people have access to it. People tend to try
what they have at hand before looking for alternatives. PHP's success is
that once people try it they tend to keep using it. Because it works.
Another really important factor to PHP's success has been the dynamic
community that has been built up behind the language. There are support
Web sites, mailing lists, and user groups around the world, working
to help each other with problems common to Web development. People like
being part of a community, and given the open-source nature of PHP, this
community is driven by personal pride and motivation, not financial benefit.
This gives it a friendly and supportive feel that people like.