If you've ever done any perl programming, or if you've spent any time talking to perl programmers, you have probably heard of "CPAN" - the Comprehensive Perl Archive Network. CPAN provides a central repository of perl modules, most of which are made available under the same licenses as perl itself (the GPL and The Artistic License). In many ways, CPAN has been "the killer app" that has made perl one of the most popular languages around. By using CPAN, a perl developer can quickly assemble the majority of the code needed for their programs, leaving them to simply code the glue needed to stick all the modules together into a cohesive whole.

The PHP Extension and Add-on Repository (PEAR) project is an effort to develop a repository similar to perl's CPAN and TeX's CTAN for the PHP community. PEAR will offer much more than the useful, but rather ad-hoc code snippets in the Code Gallery available on Zend's web site. By providing an infrastructure and defining a set of standards that all contributors must adhere to, PEAR, combined with PHP 4, may be just what is needed to take PHP to the next level.

The intention behind PEAR is to provide a means for library code authors to share their code with other developers, to give the PHP community an infrastructure for using third-party code, to define standards that help developers write code that runs in different PHP configurations, and to provide tools for code maintenance and distribution.

- Stig Bakken, PEAR Documentation