## Simple Javascript implementation

http://codeflow.org/entries/2010/aug/28/integration-by-example-euler-vs-verlet-vs-runge-kutta/

## Orbital

This one is promising, Code in python:

https://github.com/RazerM/orbital

Some of the provided examples:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 | # Create circular orbit with 90 minute period orbit1 = KeplerianElements.with_period(90 * 60, body=earth) plot(orbit1, title='Orbit 1') # Create molniya orbit from period and eccentricity from orbital.constants import earth_sidereal_day molniya1 = KeplerianElements.with_period( earth_sidereal_day / 2, e=0.741, i=radians(63.4), arg_pe=radians(270), body=earth) plot(molniya1, title='Molniya 1') # Create circular orbit at altitude 300 km orbit2 = KeplerianElements.with_altitude(300 * kilo, body=earth) plot(orbit2, title='Orbit 2') # Create molniya orbit by specifying altitude at perigee. # This works because M0=0 (perigee). molniya2 = KeplerianElements.with_altitude( 508 * kilo, e=0.741, i=radians(63.4), arg_pe=radians(270), body=earth) plot(molniya2, title='Molniya 2') |

## Orbit Hopper

2D Godot game:

https://github.com/grzala/orbit_hopper/