I have created an exposition of Hamilton's stationary action that is visualization based. The visualizations consist of interactive diagrams. Each diagram represents a case where the visitor can sweep out a range of trial trajectories (using a slider), to home in on the true trajectory.

The three main diagrams have multiple sliders, allowing the visitor to make a local adjustment to the trial trajectory. The diagrams display how the kinetic energy and the potential energy respond to change of the trial trajectory.

http://www.cleonis.nl/physics/phys256/energy_position_equati...

The objective of the exposition is to make Hamilton's stationary action entirely transparent.