Unit testing, mock objects and web testing framework for PHP built around test cases. If you know JUnit/JMock or some of the PHPUnit clones this will need no explanation. Includes a native web browser for testing web sites directly (no JavaScript).
ajaxUnit is a way of unit-testing AJAX apps that are written in PHP & Javascript The test software can put your app in a predetermined state then compare the responseText from the XMLHttpRequest object with what you are expecting.