CodeIgniter

CodeIgniter is our PHP framework of choice if your application calls for custom architecture and functionality. Sometimes it makes sense to build on top of a Content Management System such as Wordpress, Drupal, or Joomla depending on the requirements, but there are definitely times when a custom app architecture is more elegant. CodeIgniter is open-source, lightweight, super-fast, flexible, well-documented and has a great developer community. If you want the benefits of CodeIgniter, but also the benefits of a CMS or publishing platform, well there's a great system built on top of CodeIgniter called ExpressionEngine.