javascript n-body simulation dressed up frivolously. one theme is an image from oliver jeffer's book 'How to catch a star'. the other is based on the Kepler mission and whatever genius does their artwork. two options for the Kepler theme, one a star cluster and the other a set of four stars each with three planets orbiting.
clusters are set up as Plummer spheres in virial equilibrium. planetary systems are randomized but are spaced to be Hill stable, with initial eccentricities less than 0.05, and mutual inclinations less than 1 degree. all the bodies shown are included in the gravity calculation. time integration is with a leapfrog integrator with a fixed global timestep.
website here: http://nickolas1.com/nbrowser/