PHP Manual
PHP at the Core: A Hacker's Guide
Preface
Memory management
Working with Variables
Writing Functions
Writing Classes
Working with Resources
Working with INI settings
Working with streams
The "counter" Extension - A Continuing Example
The PHP 5 build system
Extension structure
PDO Driver How-To
Extension FAQs
Zend Engine 2 API reference
Zend Engine 2 Opcodes
Zend Engine 1
Error handling
Zend Engine 2 API reference
PHP at the Core: A Hacker's Guide
PHP Manual
Extension FAQs