Java Applets
I have some links that run Java Applets. They may not run on your system because the latest version of Java has a default security setting to block them. If that is the case, you can do one of two things - lower (temporarily) the security setting OR allow access to the individual site.
First, find your Java Control Panel. I found mine in the "all programs" list (look for Java, configure Java).
Click the security tab.