A long time ago I had already found the project Processing, but then somehow forgot about it again.
Two days ago I was looking at this Java-Animation-Framework again, this time with the funny “World of Sand” Java Applet or more precisely with the derivative Hell of Sand.
According to Wikipedia, Processing is suitable for beginning programmers and designers, to develop visual animations and for prototyping.
The advanced hobby developer immediately notices that it is nothing more than Java. To get a complete Java program, you only have to pack a few imports and so on around the so-called PDE code.
I sat down earlier to build something simple. My little work can be seen here as a Java applet. (Note: Just click in it with the mouse.)
Great thing of this Processing - and OpenSource (LGPL) at that.