Robot framework - Robot Framework is a generic test automation framework for acceptance testing and acceptance...
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.
STAF - The Software Testing Automation Framework (STAF) is an open source, multi-platform, multi-language...
Sauce Labs - Test mobile or web apps instantly across 700+ browser/OS/device platform combinations - without infrastructure setup.
Browsershots - Browsershots makes screenshots of your web design in different browsers.
PhearJS - Render any dynamic Javascript webpage to JSON with PhantomJS.