As the default simulation played out beautifully on-load, I immediately started to question: "hang on, I thought there wasn't a solution for 3 bodies, but this looks stable".
Before I could complete the thought, it fell apart magnificently :)
The default configuration is a special case. They are all in a stable orbit around the common barycenter, always forming an equilateral triangle. We actually have closed form solutions for this kind of configuration.
These are meta-stable, in that only a perfect initial state (positions and velocities) will be stable. Even then, I expect quantum uncertainties would kick in at some point. (In the simulator, the default system goes unstable at about 500 seconds, probably due to the limits of floating point math.)
Before I could complete the thought, it fell apart magnificently :)