These are optimised Direct3D drivers, made by Chris Dohnal, for Unreal Tournament, supporting D3D9, for those who doesn't like the OpenGL option and have better performance with D3D.
It's a couple new files that go in the UnrealTournament\System directory. To use it, change video drivers in UT, select show all devices, and then select Direct3D9 Support. If the OpenGL renderer doesn't work right on your system for whatever reason (video driver problems or some other issue), you can try using this one instead. It has mostly the same feature set as the updated OpenGL renderer. Note that this Direct3D9 renderer doesn't support selection in the editor, so consider it unsupported and not fully functional as far as use with the editor is concerned.
For more information and future upgrades, keep an eye on: