Billiard is a project mainly written in Java, based on the GPL-2.0 license.
A simple Java program in which some balls collide
Billiard is a sandbox-like Java application in which a user defined number of balls runs around and collides.
The simulation of collisions is done using continuos time, even if the concept of time in the application is discrete.
It's possible to define mass and speed for each object, even when the simulation is active.