Poisson Process javascript program, by Jeffrey Rosenthal, related to this book. Description at the bottom.

This program simulates a two-dimensional "Poisson process" where each point is placed uniformly and independently over the entire region, and yet various patterns emerge by chance alone. Keyboard shortcuts (you might need to click on the canvas first): 'o' or space to add one more point; 't' to add ten more points; 'f' to add fifty more points; or 'c' or 'r' to clear all the points.

This program is written by Jeffrey Rosenthal. See also my other JavaScript, my Stochastic Processes book, and my Java Applets.