When gamers get their hands on the PS4 later this year all they will see when booting the console is the latest versionof Sony’s PlayStation user interface. But the move to an x86 architecture gave Sony a lot of options for the underlying operating system it could use on the machine. You may be surprised to find they chose FreeBSD.

If you’d asked me to guess, I would have said the PS4 runs some form of Linux, but apparently Sony selected FreeBSD due to its more liberal licensing. The discovery of what OS is being used comes via images of a second generation PS4 development kit’s GRUB loader.

Sony has actually modified FreeBSD 9.0 to suit the PS4 hardware and called it Orbis OS. Those modifications include developing the drivers required to use AMD’s 8-core CPU and Radeon GPU combination–something FreeBSD doesn’t have in the form of a Catalyst driver. It seems unlikely those drivers will be shared with the wider FreeBSD community, though.

Although it’s an x86 platform and FreeBSD is being used, I doubt very much Sony will choose to offer access to the machine’s underlying OS or any operating system for that matter. Linux was initially an option on the PS3 as part of the OtherOS feature, but security fears eventually saw Sony remove it from the console much to the anger of those gamers who took advantage of it. They won’t risk that again.

Now read: Sony has no plans to drop PS3 price before or after PS4 launch