Bean Scripting Framework (BSF) is a set of Java classes that provides
scripting language support within Java applications and access to Java
objects and methods from scripting languages. BSF allows writing JSPs
in languages other than Java while providing access to the Java class
library. In addition, BSF permits any Java application to be
implemented in part (or dynamically extended) by a language that is
embedded within it. This is achieved by providing an API that permits
calling scripting language engines from within Java as well as an
object registry that exposes Java objects to these scripting language
engines.

This BSF package currently supports several scripting languages: *
Javascript (using Rhino ECMAScript, from the Mozilla project)
* XSLT Stylesheets (as a component of Apache XML project's Xalan and
Xerces)

In addition, the following languages are supported with their own
BSF engines: * Java (using BeanShell, from the BeanShell project)
* JRuby
* JudoScript