A few simple N-body simulations built using Simple 2D and Ruby 2D.

nbody.c and nbody.rb represents celestial bodies with varying masses, all attracted to each other. Run using make and ruby nbody.rb, respectively. Watch the video of it in action.

nbody_single.c and nbody_single.rb represents celestial bodies with equal masses and attraction to only a single point, the mouse cursor. Run using make single and ruby nbody_single.rb, respectively. Watch the video of it in action.