Explore Shale, a website created by Penn State Public Broadcasting, explains the process of extracting natural gas from the Marcellus shale. The website explains the process in a visual, interactive format: users can click around the site to answer common questions about this process, such as "Who regulates water usage?" and "How much water is used to frack a well?" Users can also navigate the site via directional arrows which will take them down into the drilling site, and explain the process along the way. This site is a particularly good visual explanation of how the process of fracking works. A text-only version is available as well as an "About" section, including a glossary.