Drupal-phpunit-template is a project mainly written in PHP, it's free.
A project template for getting Drupal to work with PHPUnit
This is a simple template / folder structure for getting PHPUnit to work with Drupal.
The unittests folder should be added to the root of your Drupal installation. It is assumed that you already have PHPUnit installed - if not you can find instructions on how to obtain it from http://www.phpunit.de/manual/current/en/installation.html
When running the unit tests from the command line you should be in the Drupal root directory i.e. not the unittests directory. For example, to run the tests in ExampleTest.php:
$ phpunit ExampleTest unittests/ExampleTest.php
The idea for creating this repository came after reading Kristian Nissen's blog post title "Drupal 6 PHPUnit testing setup": http://kristiannissen.wordpress.com/2009/12/08/drupal-6-phpunit-testing-setup/