Soft Maximum - best free downloads
gravitation

AstroGrav (Windows)
... objects move according to Newton's Law of Universal Gravitation, and displays the results as they are calculated so that you can ...

AstroGrav (Mac)
... objects move according to Newton's Law of Universal Gravitation, and displays the results as they are calculated so that you can ...

Trembling Towers
... are slipping ice cubes, on the moon you have to handle low gravitation and in the lava world the stones are made of gluey broiling lava. ...

1