Zend PHP Certification Study Guide /by Zend Technologies (Author) .The first and only officially authorized book on the PHP Certification exam developed by Zend Technologies, the commercial developer of PHP. Zend's PHP Certification exam is a high-quality, carefully developed exam designed to enhance and certify the skills of the PHP professional. The Zend PHP Certification Study Guide is a concise, densely packed book that will get you up to speed quickly on the nature of the exam's questions and what to expect on exam day. It's authoritative content comes directly from those writing the exam at Zend Technologies.