A respin of Valve's SteamOS distro has been published, featuring support for Legacy BIOS and none of the limitations of the official operating system.
The name of the distribution is Ye Olde SteamOSe and features a few interesting options. For example, it works with UEFI or BIOS, it works from a DVD or a 1GB USB Stick, supports dual-boot on non-LVM non-RAID systems, and more.
Highlights of Ye Olde SteamOSe 2013-12-19 Beta 2:
• A regression in audio between the first and the second releases (added steam and desktop users to pulse-access group) has been fixed;
• Pulse config has been modified to not force a specific sound card, and to restore the card volume on boot;
• A replacement debootstrap, which will not fail at random on users' systems when generating their own image, has been added;
• All non-Free firmware from Debian Wheezy has been added;
• ntfsprogs-udeb has been added to allow NTFS resizing in the installer;
• pavucontrol has been implemented in the installation.