Recs.
Updated
"Intern is a complete framework for testing Web sites and applications. It’s built around standards like WebDriver and was designed from the ground up to be the most powerful, flexible, and reliable JavaScript testing system in the world."
"Leadfoot is a JavaScript client library that brings cross-platform consistency to the Selenium WebDriver API. Leadfoot is also the only WebDriver client library that includes an exhaustive unit test suite that verifies that results are consistently returned from all remote drivers. Through this test suite we have discovered and reported over 15 defects to upstream WebDriver server implementers."
See the Leadfoot Command object API.
"Leadfoot can be installed and used as a stand-alone WebDriver library from npm by running npm install leadfoot. However, we recommend using Leadfoot through the Intern testing framework, which provides you with all of the tools you need to write robust unit and functional tests."
Specs
Pros
Pro Actively and seriously developed
Intern has been evaluated at http://www.slant.co/topics/2814/~what-are-the-best-node-js-selenium-webdriver-client-libraries-bindings