Selenium

*Selenium is a portable software testing framework for web applications. Selenium provides a record/playback tool for authoring tests without learning a test scripting language (Selenium IDE). It also provides a test domain-specific language (Selenese)[1] to write tests in a number of popular programming languages, including Java, C#, Groovy, Perl, PHP, Python and Ruby. The tests can then be run against most modern web browsers. Selenium deploys on Windows, Linux, and Macintosh platforms. It is open-source software, released under the Apache 2.0 license, and can be downloaded and used without charge.

Selenium Web Driver is the successor to Selenium RC. Selenium Web Driver accepts commands (sent in Selenese, or via a Client API) and sends them to a browser. This is implemented through a browser-specific browser driver, which sends commands to a browser, and retrieves results. Most browser drivers actually launch and access a browser application (such as FireFox or Internet Explorer); there is also an Html Unit browser driver, which simulates a browser using Html Unit.*

http://en.wikipedia.org/wiki/Selenium_%28software%29

really for Functional Test-s