This property contains a read-only reference to a JavaPackage that sits at the top of the Java package hierarchy; the root node of the tree. A JavaPackage is a container for other JavaPackage objects and JavaClass objects. By default, the Netscape Navigator browser will have three packages belonging to this top level node (java, sun and Netscape). Each of these is a package and will contain other packages. There may be additional externally supplied packed over and above these default three items.
MSIE supports different mechanisms for encapsulating Java code.