SeleniumHQ

WebDriver is a tool for automating web application testing. Selenium-WebDriver was developed to better support dynamic web pages where elements of a page may change without the page itself being reloaded. WebDriver’s goal is to supply a well-designed object-oriented API that provides improved support for modern advanced web-app testing problems. The primary new feature in Selenium 2.0 is the integration of the WebDriver API. Selenium-WebDriver makes direct calls to the browser using each browser’s native support for automation. How these direct calls are made, and the features they support depends on the browser you are using. It drives the browser directly using the browser’s built in support for automation.