REBOUND (github.com/hannorein/rebound)

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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.

3-D Tic-Tac-Toe (Atari 2600) online game (atarionline.org) 3D Tic-Tac-Toe for the Atari 2600 is an adaptation of the classic tic-tac-toe game with an added dimension, making it a more challenging and engaging experience for players. The game was developed and published by Atari, Inc. in 1980. Instead of the traditional 3×3 grid, 3D Tic-Tac-Toe uses a 4x4x4 cube, providing a total of 64 cells for play.

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.