Today Google released Chromium OS, the open source project behind Google Chrome OS. Google Chrome OS is an operating system that is intended for people who spend most of their time on the web. It aims to provide a computing experience that is fast, simple and secure. The Chromium OS project as you’ll see it today is comprised of the code that has been developed thus far, our early experiments with the user interface, and detailed design docs for many parts that are under active development.

Fore more information and announcement:

http://chrome.blogspot.com/2009/11/announcing-chromium-os-open-source.html
http://googletesting.blogspot.com/2009/11/testing-chrome-os.html