RSPA stands for Really Simple PHP and AJAX. It is a framework with components for processing browser events on the server using AJAX to provide interaction between the browser and the server without page reloading.
It can be used for calling PHP class functions from the browser side. It provides means to manipulate JavaScript objects on the browser page.
It can be used to manipulate common HTML page elements. It also provides custom page elements such as labels and auto-complete inputs.
It now works with PHP 4 and PHP 5