This applet is meant to be semi-educational. Items (LightComponents) are placed in a LightContainer in order to demonstrate various light properties such reflection, colors and attenuation.
I originally wrote this applet in 1996. At the time Java was new and exciting. The applet was written for JDK 1.0 with AWT (before Swing, etc.). It was targeted for Netscape (the browser at the time), but it now works just fine with Firefox (and hopefully IE). Surprisingly only minor changes were required to get it working in 2007.
My design philosophy has become more conservative over the years. At the time the monochrome light elements and windows without borders seemed minimalist and cool. I've reworked the interface a bit with version 1.2. It now uses Swing instead of AWT. Also, various usability enhancements have been made such as allowing light components to be dragged. Minor changes with loading images in 2008 brought the version up to 1.3.
Originally this program was written using Symantec Cafe. I updated it in 2007 using Eclipse (which I recommend trying). To run this in Eclipse import this archive into a new project and select "Run As" and then "Applet".
Hopefully the interface is clear enough now that you'll be able to figure it out without step by step instructions. Try selecting the Options / View Pallet menu. The bubble help will help you figure out which light component is which.
Once you have selected a few light components, at least one of which should be a laser, try moving them around by dragging them with the mouse. Try arranging them so that the laser beams intersect various light components, particularly mirrors, at different angles. Drag the green circles in order to rotate light components. Right click on light components and select "Properties" (or Alt-Enter) to make various adjustments to the selected light component. The property that might be the most fun to play with is the color which can be adjusted by clicking the "Color" button. Right click a light component and select "Delete" (or the delete key) to delete the selected light component. When the light components are the way you want them select Options / Run to begin the simulation.
Additional menu items that might be helpful include File / New to delete everything and start over again. Click File / Properties to adjust the properties for the entire light container. The property for the light container that might be fun to adjust is "Visibility". Try large numbers to make the light go farther before it fades away.