14 DAY TRIAL // Valve is preparing for the release of their Steam Machines, and they are making sure that SteamOS is perfectly capable of dealing with all sorts of controllers, including the ones from Xbox 360 and Xbox One.
Valve knows that it will have to deliver a stable and easy-to-use operating system with their Steam Machines. SteamOS is a Debian-based distribution that basically uses the Steam Big Picture as the desktop environment, but it has all the other components. If you really want to, you can even get a limited GNOME 2 desktop and install most of the apps from the official repositories. It's worth noting that SteamOS is not meant to work as a regular Linux distribution, but that doesn't mean that it can't.
The SteamOS developers are doing something that is not all that common in the industry. Because SteamOS is a Linux distribution, it's hard to keep people from using whatever controllers they want. They could just as easily make the OS work only with their Steam Controllers, but have no intention of limiting the Linux players, and people will be able to use pretty much anything they want.
New SteamOS Brewmaster version is out
Valve has a new version of SteamOS based on the newer Debian 8, which is called Brewmaster. It's not quite clear whether they will switch to the new version of the OS before or after the launch, but it's getting a lot more improvements than the regular edition.
According to the changelog, the system no longer hangs when pairing additional Xbox 360 wireless controllers, occasional hangs that occurred when using force feedback with Xbox 360 controllers have been fixed, the LEDs on Xbox 360 controllers now work properly, support has been added for new models of Xbox One controller, and the OS no longer locks up when connecting more than one Xbox 360 controller.
You can download the latest SteamOS from Softpedia, but please keep in mind that you will need an entire partition just for this distro and it's not deemed stable.