The operating system looks to be a special blend of Google Chrome and Android; more work to be done.
If anyone had any doubts, put them to rest because the Chromecast has been rooted. We're not surprised at this -- any device that runs an OS that accepts input will get exploited eventually -- but what the GTV Hacker crew found inside is a bit more intriguing.
Google says the Chromecast runs ChromeOS, and when you power it up it says Chrome big as life, but the folks at GTV Hacker say that's not really so. After digging into the software a little (rooting gives you access via telnet) they say what's there is closer to Android or Google TV than it is to Chrome. There are no methods to run any apps on the system, but they don't rule out the possibility of a real Android port to the $35 dongle.
If you have a powered USB OTG cable and a flash drive you can erase, you can give this a try yourself. The process seems trivial, though there's nothing you can do with it once you're finished other than look at the system files. For some of us though, that's reason enough. Let's hope content companies aren't scared off of the whole Google Cast concept now.
Source: GTV Hacker