Selenium - Selenium automates browsers. That's it! What you do with that power is entirely up to you. Primarily, it is for automating web applications for testing purposes, but is certainly not limited to just that.

QUnit - What is QUnit? QUnit is a powerful, easy-to-use JavaScript unit testing framework. It's used by the jQuery, jQuery UI and jQuery Mobile projects and is capable of testing any generic JavaScript code, including itself!

Cucumber - Cucumber is a BDD tool for specification of application features and user scenarios in plain text.

Ranorex - Ranorex is a GUI test automation framework for testing of desktop, web-based and mobile applications.

Endtest - Intelligent Test Automation

Capybara - Capybara helps you test web applications by simulating how a real user would interact with your app.