This applet is a java-based implementation of a simple 2D Ising Model on a 500 by 500 grid. The units for temperature and magnetic field energies are scaled such that the nearest-neighbor coupling constant is 1.
Note that this requires java 5 (sometimes called 1.5) or better. The latest Java can be downloaded here. For Macs, this version should work.

For questions, contact Erik Tollerud.