Sebastian Bergmann has posted some details about an update that's been made to the test runner for the PHPUnit (3.3) unit testing suite - an allowance for directories instead of just files on the command line.

Given a directory, the test runner will recursively scan the directory for *Test.php files, build a test suite out of the *Test classes, and run it.

PHPUnit is framework that makes writing tests for your code easy and also includes functionality to run the tests and analyze their results.