Adiabatically Changing Harmonic Oscillator is a free program that displays the frictionless dynamics of a mass on a spring where the angular frequency of the oscillator adiabatically changes with time according to: ω = ω0 + α tβ.
The simulation displays the cumulative and current phase space motion as well as the area in phase space.
All parameters can be changed via textboxes. You can modify this simulation if you have Ejs installed by right-clicking within the plot and selecting "Open Ejs Model" from the pop-up menu item.