Foreword

For those of you new to PHP, let me begin with a brief recap. PHPstarted in late 1994 as
a quick Perl hack written by Rasmus Lerdorf. Over the next two to three years it evolved
into what we know today as PHP/FI 2.0. Zeev Suraski and Iintroduced a new parser in
the summer of 1997 that led to PHP 3. At that time PHP syntax and semantics were
formalized, thereby establishing a foundation for growth.

Today, PHP3 has established itself as one of the most popular Web scripting languages
available. At the time of this Foreword, PHP has been installed on some 2 million Web
servers. Its salient features include:

Very short development times

Platform independence

Multiple database support

PHP has risen to an even higher level. Featuring the use of the "Zend Engine," PHP 4 is
much faster and more powerful in every respect. The new version supports multithreaded
Web server environments including an ISAPI module (Microsoft's IIS). Other features
include a new Web server abstraction layer, Java connectivity, and a much-improved
build process for better PHP configuration.

Where do we go from here? Today the major concern of entrants into the PHPcommunity
is application support. People know PHP functionality is good, but can it be backed up?
The answer is yes. Zend Technologies has arisen to give commercial backing for PHP,
thereby enabling undecided companies to take the plunge and benefit from superior open-
source software.

Leon's second edition of Core PHP Programming is also serving in a supportive role.
The second edition features:

Coverage of PHP 4's language changes and features, such as the improved include
function and the new NULL and Boolean types.

Coverage of most of PHP 4's extensions.

Tighter typesetting for readers looking for a functional reference.

Added screenshots and comments for new users interested in quickly learning PHP
functionality.

Commercial backing and reference materials will continue to drive PHP's gradual
acceptance as the standard in Web scripting.