On Dzone.com today Giorgio Sironi has posted what he considers to be some of the most popular Open Source PHP projects of 2011 including Symfony2, Doctrine and HipHop.

This non-scientific analysis of the popular and exciting PHP projects starts from researches on active projects on SourceForge and GitHub; the latter is where most of the collaboration and involvement of PHP developers is today. I've also crowdsourced the question on Twitter to catch projects I wasn't aware of, and I hope to do the same with you.

Other projects included in his list are:

• Symfony2 Components
• Moodle
• Composer and Packagist
• Drupal, Joomla, Wordpress

Have a project you think he missed? Let him know!