Much easier to deploy safely than C, its
slower performance has always been more than balanced by the
comparatively fast development cycle it offers. Even more useful has
been the increasing availability of a large number of stable code
libraries for Perl.
So where does
PHP fit in? PHP was written especially for the Web. Many of the issues
and problems faced by Web programmers are addressed within the language
itself. Whereas a Perl programmer must use an external library or write
code to acquire data submitted by the user of a Web page, PHP makes this
data automatically available. Whereas a Perl programmer must install
modules to enable her to write database-driven environments, PHP bundles
a powerful SQL database library and provides built-in support for a
whole range of third-party databases. In short, because PHP has been
created for Web programmers, it has a set of functions for almost any
typical problem you might encounter, from managing user sessions to
handling XML documents.
So, do we have to pay for this ease of
use with even slower performance? Not at all. PHP is designed to run as
a module with many server applications, which means that there are none
of the start-up overheads associated with CGI scripts. The fact that
many typical tasks are handled by PHP means that developers are freed
from reliance on utility libraries that can slow things down.
It is not the case that PHP does not
provide libraries, though. Perl has the Comprehensive Perl Archive
Network (CPAN), and PHP has the PHP Extension and Application Repository
(PEAR)—its own repository of powerful packages that extend PHP's power.