"This discovery comes nicely alongside the celebration of FreeBSD's 20th birthday, for all the UNIX nerds. The operating system powering the PlayStation 4 is Orbis OS, which is a Sony spin of FreeBSD 9.0. It's not a huge surprise FreeBSD is being used over Linux, in part due to the more liberal licensing. The PlayStation 4 is x86-64 based now rather than Cell-based, which makes it easier to use FreeBSD. BSDs in general currently lack manufacturer supported full-feature AMD graphics driver, which leads to the conclusion that Sony and AMD have likely co-developed a discrete driver for the PS4. Some pictures of the development kit boot loader (GRUB) have been published too."