From my understanding, SteamOS is locked down in that all you can do is play games and surf the web. You can not install any software within SteamOS without hacking it. You can install another Os beside it but nothing within it without hacking it."Locked down" is probably a poor choice of words. Yes, it'll be Linux kernel + video drivers + Steam client and games right out of the box, but you'll be free to install any other Linux software or a desktop environment if you want to without molesting the rest of it. SteamOS won't come bundled with extraneous software, but it's not going to restrict installation of other packages either.