This Java applet was written by Michael J. McGuffin, November 2004, University of Toronto. Feel free to use/copy/modify the applet for educational or research purposes. To copy, download the Java source code and compile it, or download all files in this directory. To change the colours used in the applet, change the values for the param tags in the html source file.
For those interested in modifying the source code, one potential improvement would be to have the applet automatically increase the density of fluxlines drawn in regions where the direction of the field changes rapidly, and/or to draw the flux lines through all critical points.