External References about Maintaining and Extending PHP

Books

• Extending and Embedding PHP Sara Golemon's book on PHP (2006)
• Advanced PHP Programming George Schlossnagle's book has several relevant chapters (2004)

Blog Posts and Articles

• Blog Series on Internals by Anthony Ferrara & Nikita Popov (2012)
  • PHP's Source Code For PHP Developers - Part 1 - The Structure
  • Understanding PHP's internal function definitions (PHP's Source Code for PHP Developers - Part 2)
• Fixing a bug in php-src François Gannaz describes making his very first bug fix (2012)
• Series by Kristina Chodorow (2011)
  • PHP Extensions Made Eldrich: Installing PHP
  • PHP Extensions Made Eldrich: Hello, World!
  • PHP Extensions Made Eldrich: PHP Variables
  • PHP Extensions Made Eldrich: Classes
• References and foreach Blog post by Johannes Schlüter (2010)
• Wrapping C++ Classes in a PHP Extension Zend DevZone article (2009)
• Zend DevZone Series by Sara Golemon (2005, 2006)
  • Extension Writing Part I: Introduction to PHP and Zend
  • Extension Writing Part II: Parameters, Arrays, and ZVALs
  • Extension Writing Part II: Parameters, Arrays, and ZVALs (continued)
  • Extension Writing Part III: Resources

Conference Slides

• PHP Extension Writing Conference slides by Johannes Schlüter and Marcus Börger (2009)
• Extending PHP Conference slides by Wez Furlong (2003)