REBOUND (github.com/hannorein/rebound)

excerpt

REBOUND is an N-body integrator, i.e. a software package that can integrate the motion of particles under the influence of gravity. The particles can represent stars, planets, moons, ring or dust particles. REBOUND is very flexible and can be customized to accurately and efficiently solve many problems in astrophysics.

Renton (Wikivoyage) Renton is a city in King County, Washington south of Bellevue and north of Kent. It is a quiet suburb of Seattle at the base of Lake Washington. Renton is primarily known as the site of the Boeing 737 plant, where the popular commercial jetliner is built. Renton is also notable for being the resting place of rock legend Jimi Hendrix.

n-body problem (Wikipedia) In physics, the n-body problem is the problem of predicting the individual motions of a group of celestial objects interacting with each other gravitationally. Solving this problem has been motivated by the desire to understand the motions of the Sun, Moon, planets, and visible stars. In the 20th century, understanding the dynamics of globular cluster star systems became an important n-body problem. The n-body problem in general relativity is considerably more difficult to solve due to additional factors like time and space distortions.