Microsoft DirectX is a collection of application programming interfaces (APIs) for handling tasks related to multimedia, especially game programming and video, on Microsoft platforms. Originally, the names of these APIs all began with Direct, such as Direct3D, DirectDraw, DirectMusic, DirectPlay, DirectSound, and so forth. The name DirectX was coined as shorthand term for all of these APIs (the X standing in for the particular API names) and soon became the name of the collection.
DirectX 9.0c - DirectX 9.0c will help improve multimedia experiences on most PCs. This latest version of DirectX offers better security, updated graphics, faster frame rates, and support for massively multiplayer games. It also features more immersive audio when running and displaying programs rich in multimedia elements such as full-color graphics, video, 3-D animation and surround sound. If you had an earlier version of DirectX installed on your system, you will see little difference in available space on your hard drive following the installation. DirectX 9.0c will overwrite any earlier versions. This release also resolves a number of minor bugs and includes security updates.
Latest version (Aug 09) : Download
DirectX 10 - A major update to DirectX API, DirectX 10 ships with and is only available with Windows Vista and later; previous versions of Windows such as Windows XP are not able to officially run DirectX 10-exclusive applications. There are unofficial ports of DirectX 10 to XP, however these do not always work reliably. Changes for DirectX 10 were extensive.
Many former parts of DirectX API were deprecated in the latest DirectX SDK and will be preserved for compatibility only: DirectInput was deprecated in favor of XInput, DirectSound was deprecated in favor of the Cross-platform Audio Creation Tool system (XACT) and lost support for hardware accelerated audio, since Vista audio stack renders sound in software on the CPU. The DirectPlay DPLAY.DLL was also removed and was replaced with dplayx.dll; games that rely on this DLL must duplicate it and rename it to dplay.dll.
Latest version : DirectX 10 RC2 XP Fix 3
DirectX 11 - With the major scheduled features including GPGPU support (DirectComputer), tessellation support, and improved multi-threading support to assist video game developers in developing games that better utilize multi-core processors. Direct3D 11 will run on Windows Vista, Windows 7, and all future Windows operating systems. Parts of the new API such as multi-threaded resource handling can be supported on Direct3D 9/10/10.1-class hardware. Hardware tessellation and Shader Model 5.0 will require Direct3D 11 supporting hardware. Microsoft has since released the Direct3D 11 Technical Preview. Direct3D 11 is a strict superset of Direct3D 10.1 - all hardware and API features of version 10.1 are retained, and new features are added only when necessary for exposing new functionality.
Microsoft released the Final Platform Update for Windows Vista on October 27, 2009, which was 5 days after the initial release of Windows 7 (launched with Direct3D 11 as a base standard).
