Patch Tester is a Joomla extension that allows you to easily apply changes from pull requests. This extension helps Joomla community members to test Joomla CMS bug fixes.
Download the component at: https://github.com/joomla-extensions/patchtester/releases/tag/2.0.beta
You can see a video tutorial here: http://www.youtube.com/watch?v=4OWgusZgIfk&feature=youtube_gdata
Patch tester component was originally created by Ian Maclennan, and has been improved by Nikolai Plath and Michael Babker.
You can find most updated source code at: https://github.com/joomla-extensions/patchtester