Physics-based simulation of a chain of several rigid bodies connected by flexible joints, using the 2D Rigid Body Physics Engine.
Click near an object to exert a force with your mouse. Try changing gravity, elasticity (bounciness), and damping (friction).
Experiments to try:
The resting chain follows a curve called a Catenary. With calculus you can predict this curve.
Each chain link is a single rigid body. There are "joints" attaching each chain link to its neighbors or to the background.
Also available are: open source code, documentation and a simple-compiled version which is more customizable.