This white paper describes techniques to generate shadows on mainstream graphics hardware in realtime. Shadows make a 3D scene more realistic and while Shadow Maps suffer from anti-aliasing artifacts due to low-precision textures, Shadow Volumes avoid this problem by creating physically accurate shadows. However, if there are many dynamic shadow-generating objects or if there are a lot of moving light sources, this technique could severely affect performance. This paper describes how shadow volumes generated on the CPU using a multithreaded approach could free up the graphics hardware from this bottleneck-creating task.