Firefox OS

http://www.mozilla.org/en-US/firefoxos/

* all apps are and will be created from CSS, JavaScript, and HTML
* the OS is open source
* each app runs as its own virtual Firefox/browser process
* installing apps from Mozilla Marketplace is incredibly easy
* support for mobile will push Firefox to keep improving performance
* more!

>>1
Wow. I wouldn't use it but it's good to see it exists.

>>2
Have you no respect for the prototyping and learning process? One of the best ways to learn things is to experience things. You may or may not fail while you do it. You will certainly not learn anything if you pre-judge everything as not worthwhile.