Microsoft has published the official Direct3D 12 headers under the MIT license, which allows you to use them in any project and make your own changes … Previously, these files were supplied as part of the Windows SDK under a proprietary license. Along with the header files, assembly scripts for CMake, auxiliary components to improve portability between Windows and WSL (Windows Subsystem for Linux), as well as a layer for the separate use of header files in Linux environments, allowing you to do without installing the Windows SDK are published.
The header files were opened as part of an initiative to implement in WSL2 (Windows Subsystem for Linux) tools for accessing the GPU and running graphical Linux applications. To organize the output of the Linux application interface to the main Windows desktop, Microsoft is developing its own composite manager based on the Wayland protocol. OpenGL support is provided through an interlayer that translates calls to API DirectX 12. For Linux, the libd3d12.so library is also prepared, similar in functionality to d3d12.dll and providing a full-fledged Direct3D 12 graphics API.