For years now , Valve has been slowly improving the capabilities of the Proton compatibility layer that lets thousands of Windows games work seamlessly on the Linux based SteamOS . But Valves Windows to Linux compatibility layer generally only extends back to games written for Direct3D 8, the proprietary Windows graphics API Microsoft released in late 2000. Now, a new open source project is seeking to extend Linux interoperability further back into PC gaming history. The d7vk project describe
