LiveConnect was essential in many Web applications. The sandbox model prevents a Java applet from accessing the browser and its properties. As Java became more and more popular, there was an effort in Netscape to create a version of its browser entirely based on Java. Out of that effort came Rhino, which is now an open source effort under Mozilla.org. Named from the animal on the cover of the O'Reilly book about JavaScript, Rhino gives the Java developer a compact JavaScript engine.
Many applications require a scripting engine for performing specific tasks or for customization.
JavaScript, with its popularity and simple syntax, is a good match for such applications and Rhino offers a good implementation.