Amazing web model of tearing cloth

Click on the link and a web page with a piece of cloth (looks like a piece of graph paper) will appear. Click and drag across the cloth and you’ll rip it. The simulation is very realistic, complete with gravitational physics.

Even better, if you right click (hold down the control key), your mouse turns into a cutting tool.

And as a pièce de résistance, all the code is there to play with and learn from, including the HTML, CSS, and Javascript. Absolutely brilliant.