dgVoodoo is a graphics wrapper and API emulator primarily designed to enable older DirectX-based games to run smoothly on modern Windows systems. It provides a way to emulate the functionality of older graphics APIs like DirectX 1-7, allowing games that originally used these APIs to run on newer hardware that may not support them directly. dgVoodoo aims to improve compatibility, enhance graphics rendering, and enable features like higher resolutions and better performance for these legacy games.