<p>Is an opensource/commercial tool/framework, available for automated web app testing in Google Chrome browser on Windows XP / Vista? ( An alpha/beta Tool is also OK)</p>

<p>Thanks</p>

Selenium supports Chrome pretty much out of the box because it works by injecting javascript in the web page.
http://selenium-rc.openqa.org/
Webdriver has an early version of Chrome driver.
http://code.google.com/p/webdriver/
Both are open source and works on Windows.