Source : Free On-Line Dictionary of Computing

DirectX
     
         A {Microsoft} programming interface
        {standard}, first included with {Windows 95}.  DirectX gives
        (games) programmers a standard way to gain direct access to
        enhanced hardware features under Windows 95 instead of going
        via the Windows 95 {GDI}.  Some DirectX code runs faster than
        the equivalent under {MS DOS}.
     
        DirectX promises performance improvements for graphics, sound,
        video, 3D, and network capabilites of games, but only where
        both hardware and software support DirectX.
     
        DirectX 2 introduced the Direct3D interface.  Version 5 was
        current at 1998-02-01.  Version 8.1 is included in {Windows
        XP}.
     
        Current version: 8.1 (as of 2001-12-31).
     
        {Home (http://www.microsoft.com/directx/)}.
     
        (2001-12-31)