Mozilla Foundation at the MWC 2012 showed its New Platform that called "Boot2Gecko", a cloud based open-source Mobile OS, Which is coded entirely with HTML5, CSS and Javascript.

Boot2Gecko is using the latest open web standards for its apps, which means that apps written for it will be compatible with just about any smartphone running the OS, or even every device with an HTML5-enabled browser. And do not worry even though the OS itself is cloud-based, you might still use your phone offline and even run apps and games on it offline caching is a technology already supported by the web standards.

Check out all "B2G" OS Screenshots

The Mozilla team had the platform installed on a Samsung Galaxy S II and were doing all the demoes on the Samsung former flagship, but the company is actually looking to release a completely different device. Its aim is to produce an ultra-cheap smartphone, powered by a 600 MHz CPU and packing just 256MB of RAM.