Why won't Java applets run in my browser?
Answer: Java applets can be really cool when they work. They allow interactive programs like calculators and games to run directly in your browser window. Unfortunately, applets require full Java support or they won't run at all. What makes this such a big problem is that Netscape and Internet Explorer use different Java interpreters. So one Java applet might run fine on Jane's PC running Internet Explorer, but might not run at all on Peter's Mac which is running Netscape.
The best way to solve the errant Java problem is to have the two latest versions of both browsers on your computer. If an applet won't run on one browser, try the other one and it probably will. Fortunately, most web programmers go through the painful process of making their applets compatible with both IE and Netscape. However, since that's not always the case, it's a good idea to have both browsers on your computer.