The Unreal Tournament SDK is state-of-the-art Toolset / Engine Enhancement for retail Unreal Tournament, that let's you create anything you want. Sci-Fi Battle Scenes, a Strategy Game, a Fun Mod, Survival-Horror Shooter, Simulations - Everything. It will also include a Sandbox showcasing the New Possibilities via bundled Mini-Mods / Demos made by Fans and me. It enhances the render engine, gameplay, unreal script features and anything UT Veterans ever dreamed off. It is completely Open Source, free for noncommercial use.
Now the bounding volume system supports particle events too! Here you see particles flying towards a volume brush. While they're entrancing they change their color (just a simple example)