SimpleTest is a nice testing framework for testing PHP-based applications at the unit and functional level. However, I (and others) have had trouble getting JUnit-compatible XML output for use in continuous integration servers like Jenkins.
SimpleTest provides a built-in XML-based output, but it seems to be mostly for internal communication by SimpleTest itself. It's not JUnit compatible.
To convert SimpleTest output into JUnit-compatible XML, I've seen at least a few posts :