DirectX is only available for Windows, but is a free add on, not a formal Windows component. From the user point of view, it is a downloadable/installable package of drivers and DLLs. Programmers see additional components not required by end users.
DirectX is an alternative to Graphic Display Interface (GDI) and Multimedia APIs built into Windows. In general, it offers more capability and better performance. The downside is that every Windows PC supports GDI and Multimedia whereas DirectX must be explicitly installed on Windows 95 PCs. Windows 98 ships with DirectX installed, but there are many versions of DirectX, and a given program may require that DirectX be upgraded before it will work properly.
There is a competing technology known as OpenGL that is multiplatform. In general, OpenGL has been used for CAD and business applications as well as multiplatform programs. DirectX has been used for Windows games. There is considerable overlap between OpenGL and DirectX.
http://www.clipcode.net/content/directdraw_direct3d_guide/01_overview.htm
Relationship to Windows GDI and Multimedia APIs
Return To Index Copyright 1994-2008 by Donald Kenney.