PHP RSS Reader comes with a complete admin panel where every setting can be controlled.The application creates SEO-friendly URLs for every category & article which is important for anyone who will use PHP RSS Reader for creating a feed-based website rather than using it as a personal feed-reader.

Todoyu is an open source task/project management, time tracking & collaboration application that is built with PHP. The application has a modern, Ajaxed interface where both users & clients can have roles on projects.

The Ajax Availability Calendar is a php script designed to show availability of whatever you might need it for (eg. holiday cottage, hotel rooms etc.). 
Free to use on your website or application and is currently being used (v.2) by hundreds, if not thousands, of websites around the world.