Wine - Open Source Software for running Windows applications on other operating systems.
DXVK - Vulkan-based D3D11 implementation for Linux / Wine
CodeWeavers CrossOver - Don't buy a Windows license, don't reboot and don't use a Virtual Machine. Try a free trial of CrossOver to run your Windows software on Mac, Linux and Chrome OS.
DXUP - A D3D10 -> D3D11 Translation Layer
PlayOnLinux - PlayOnLinux will allow you to play your favorite games on Linux easily
Direct3D 9-to-11 - Direct3D 9 to Direct3D 11 converter.