This is the eBook version of the printed book. If the print book includes a CD-ROM, this content is not included within the eBook version. Over the past three years PHP has evolved from being a niche language used to add dynamic functionality to small sites to a powerful tool making strong inroads into large-scale, business-critical Web systems. The rapid maturation of PHP has created a skeptical population of users from more traditional 'enterprise' languages who question the readiness and