DirectX 9.26.1590 (March 2009), End-User Runtime and Developers SDK

The March 2009 DirectX SDK download contains the tools needed to build cutting-edge, media-rich, interactive applications. It includes runtimes, headers and libraries, samples, documentation, utilities, and support for C++ development.

The March SDK also includes an update to the Technical Preview for Direct3D 11, the latest version of Direct3D that provides support for tessellation and general purpose GPU processing, as well as the Technical Preview for Direct2D and DirectWrite, the new Windows APIs for accelerated 2D rendering and font and text rendering. Further changes in the March SDK include improvements to the audio tools and the new XNA Math library.

Source- Tech Today