BY NOW YOU PROBABLY ALREADY HAVE A VERSION OF PHP installed on at least one system and you've been using it to develop web-based applications. You might have downloaded the Win32 build from php.net to run on IIS or Apache for Windows, or used your *nix distribution's (Linux, BSD, or another POSIX-compliant distribution) packaging system to install binaries created by a third party.
The PHP Life Cycle
Variables from the Inside Out
Memory Management
Setting Up a Build Environment
Your First Extension
Returning Values
Accepting Parameters
Working with Arrays and HashTables
The Resource Data Type
PHP4 Objects
PHP5 Objects
Startup, Shutdown, and a Few Points in Between
INI Settings
Accessing Streams
Implementing Streams
Diverting the Stream
Configuration and Linking
Extension Generators
Setting Up a Host Environment
Advanced Embedding
Appendix A. A Zend API Reference
Appendix B. PHPAPI
Appendix C. Extending and Embedding Cookbook
Appendix D. Additional Resources