(Update 10/26/2010 – A version of Detonator for Unity 3.0 is now available.)
Detonator is an extension for Unity3D that lets you make good looking explosions quickly and easily for your Unity projects. How you use it depends on who you are and what your goals are. Solo coders can quickly get prototype explosions going while artists can stack effects to quickly make complex explosions.
Detonator was created originally for the Unity Summer of Code 2009.
Sorry, the Unity 3.x and earlier versions of Detonator are no longer supported. Please grab the latest version from here. However feel free to drop notes in the comments as I or other users may be able to help.