Giving visitors a chance to evaluate and rate content is an extremely common pattern on content-rich websites. In addition to giving visitors a way to jump to the best content, it can give you—the site’s administrator—a way to determine what content on your site is most effective.

Almost all rating and evaluation modules for Drupal rely on a shared module called Voting API. Though it offers no features for your site on its own, it gives developers a set of tools for building rating systems and provides a common format for storing votes and calculating the results. This allows developers to focus on what makes their work unique (presenting vote results in a novel way, for example) while Voting API handles the grunt work.