GitHub: 22
Stack Overflow: 21
Description: P4A (PHP For Applications) is probably the best PHP5 RAD and object oriented PHP framework for building event-driven stateful web applications.
Language: PHP
Framework Link: http://p4a.sourceforge.net/
GitHub Link: https://github.com/fballiano/p4a
Stack Overflow Questions: http://stackoverflow.com/questions/tagged/p4a