Selenium: "Selenium is a test tool for web applications. Selenium tests run directly in a browsers, just as real users do. And they run in Internet Explorer, Mozilla and Firefox on Windows, Linux and Macintosh. No other test tool covers such a wide array of platforms.
Selenium was developed by team of programmers and testers at ThoughtWorks. It is open-source software and can be downloaded and used without charge." (Thanks, John) 10:25:12 PM