Wikipedia
OE-Cake, OE-CAKE! or OE Cake is a 2D fluid physics sandbox which was used to demonstrate the Octave Engine fluid physics simulator created by Prometech Software Inc.. It was one of the first engines with the ability to realistically process water and other materials in real-time. In the program, which acts as a physics-based paint program, users can insert objects and see them interact under the laws of physics. It has advanced fluid simulation, and support for gases, rigid objects, elastic reactions, friction, weight, pressure, textured particles, copy-and-paste, transparency, foreground and background images, and easy file sharing.
OE-Cake was eventually superseded by the no-longer available PhysiCafe program, which was a web-app demonstration of the same engine.
The name OE-Cake comes from the name of the engine and the word "cake" loosely means "draw" in Japanese; its name therefore means "OctaveEngine Draw".