jQuery-Claypool is a railable javascript application framework that runs on the client and, thanks to Envjs, the server. This site is running on Google AppEngine with jquery-claypool and Envjs!

JavascriptMVC is a Javascript MVC framework that uses Envjs as part of it's testing triage including in browser, Selenium, and headless testing with Envjs.

The Blue Ridge JavaScript Testing Rails Plugin adds support for command-line and in-browser JavaScript unit tests to your Rails app. It bundles several great tools (including env.js) together in a convention-over-configuration, Rails-like way.