Let's you know what's up with your Java environment.
Wassup will tell you the System Properties, as many as the Security system will let you peek at. This includes such things as which JVM is running, which version of Java, which vendor.
Wassup may be run as either an Applet or an application. When you run Wassup as an application it shows you considerably more information. The Java sandbox considers it a security risk to reveal that information to an Applet.
As an application, you can see all the possible System Properties. When you run as an unsigned Applet, your view is much more limited. If you OK the Java sandbox security override, it will let you view the restricted properties.
NOTE: Wassup is for non military use only.