DirectX 9.0 is a set of application programming interfaces (APIs) developed by Microsoft that allows software developers to create multimedia applications, particularly video games, for the Windows operating system. Released in 2002, it introduced advanced graphics features, including support for 3D graphics, improved sound capabilities, and enhanced performance for gaming applications. One of the key features of DirectX 9.0 is its support for Shader Model 2.0, which enables more complex visual effects and realistic graphics in games. This version also improved compatibility with various hardware, allowing developers to optimize their games for a wider range of graphics cards and systems, ultimately enhancing the gaming experience for users.