Phun
I know it has been a while since I’ve posted, but this is just too much fun to not tell the world about (all six of you that read this):
Basically, you use their super-intuitive interface to draw a 2-D scene then “play” it to see how the objects interact based oh physical properties. I can sit here for hours watching balls bounce around, and irregularlly shapped objects teeter then fall on nearby houses of blocks.
Back in college there was a program called “xaero” that did something similar (but in 3-D) but you could not add objects while the simulation was going. This ability makes Phun even more so (fun, that is).
If you don’t want to go through the trouble of downloading and installing, you can watch some videos of it in action here: