DirectX is a Microsoft product. DirectX is a collection of APIs for easily handling tasks related to game programming on Microsoft Windows. It is most widely used in the development of computer games for Windows. The DirectX SDK is available free from Microsoft. The DirectX runtime was originally redistributed by computer game developers along with their games, but later it was included in Windows. DirectX 9.0c is the latest version of DirectX. The latest versions of DirectX are still usually included with PC games, since the API is updated so often.

Direct3D (the 3D graphics API within DirectX) is widely used in the development of video games for Microsoft Windows, Microsoft Xbox, and Microsoft Xbox 360. Direct3D is also used by other software applications for visualization and graphics tasks such as CAD/CAM engineering. As Direct3D is the most widely publicized component of DirectX, it is common to see the names "DirectX" and "Direct3D" used interchangeably.

Updates : DirectX Updates