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.
Robot framework - Robot Framework is a generic test automation framework for acceptance testing and acceptance...
Sauce Labs - Test mobile or web apps instantly across 700+ browser/OS/device platform combinations - without infrastructure setup.
Citrus framework - Citrus Integration Testing
Browsershots - Browsershots makes screenshots of your web design in different browsers.
Cucumber - Cucumber is a BDD tool for specification of application features and user scenarios in plain text.