Linux desktop systems can now have working support for Microsoft's Direct3D 9 API via a new Gallium3D state tracker. Unlike the earlier Direct3D 10/11 state tracker for Gallium3D on Linux, this new code actually can run D3D9 games and at better performance than what's offered by Wine.
Back in 2010, Direct3D 10/11 was natively implemented for Linux
in the form of a Gallium3D state tracker. While Gallium3D is most often associated with OpenGL, its API agnostic and handles OpenGL ES, OpenVG, and even OpenCL for compute support, among other interfaces. Gallium3D can work just as well with Direct3D, but there has traditionally been not much developer interest in such a state tracker. This isn't to be confused with a translation layer whereby Direct3D commands are mapped into OpenGL.
The Direct3D 10/11 state tracker excitement was ultimately shortlived as the upstream Wine development community wasn't interested in adding support
for it since it's a Linux-only solution and at that it's limited to those using Gallium3D, which is basically the open-source Radeon and Nouveau (NVIDIA) users. This D3D 10/11 state tracker was ultimately removed from Mesa
since it wasn't being used and the code was suffering bit-rot