What is Physics Engine?
What is HTML5 Canvas?
HTML5 Canvas will become defacto standard for display graphics on the web page. The closest competitor for this is Flash, WebGL.
How to run this application?
The demo link is @ http://immense-dusk-7834.herokuapp.com/
This code is loosely inspired by http://playncoding.com/.
Get the latest codebase and do,
mvn clean package java -jar target/dependency/webapp-runner.jar target/*.war
Open the browser and type http://localhost:8080/ and follow the instructions.