I wrote this Java applet to help teach myself how to program in Java. The applet is based on the well-known program called "Life," created by John Conway. Rather than try to explain how Life works, I will refer you to Conway's Game of Life and Paul's Page of Conway's Life Miscellany, both of which contain much useful information about Life.
The applet's controls are designed to be relatively self-explanatory. To quickly see the applet in action, click "Randomize" to generate a random grid of cells and then click "Start." Use the mouse to "draw" cells onto the grid. Use the "Cell Color" and "Background Color" controls to change the color of cells and the background, respectively. Use the "Shades" control to change the number of shades of color used to draw cells. When a cell "dies," its color will gradually fade into the background color at a rate corresponding to the selected number of shades. All parameters (e.g., cell color, background color, number of shades, etc.) can be changed while the applet is running.
I have made the source code for the applet available. I have also generated and made available source code documentation generated using javadoc. All source code is Copyright 1998 by Robert Plotkin.
Please email all feedback to me at rplotkin@alum.mit.edu.