This simulation shows the Gliese 876 planetary system, as detailed in the Wikipedia article at:
If you set the simulation running, you can watch how it evolves, and see how the orbital elements of the four planets slowly change with the passage of time. If you use the Evolve / Settings... command to increase the time step to 50 days, you should be able to watch the orbital changes on the view window, particularly the precession caused by the interactions between the planets.
Since different computers run at different speeds, you may need to edit the evolution time step to get the simulation to run at an acceptable rate.
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