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.

Ranorex Studio - Accelerate testing with Ranorex Studio, the all-in-one tool for test automation. For desktop, web, or mobile app testing, with easy codeless automation tools, a full IDE, robust object recognition, flexible reporting and built-in Selenium WebDriver.

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

Froglogic Squish - Squish is a commercial cross-platform GUI and regression testing tool that can test applications based on a variety of GUI technologies.