Rhino is Java library and tools for implementing the Javascript's core component. In brief, Rhino provides

1. Javascript Shell,
2. Javascript compiler for generating Java bytecode,
3. Javascript debugger and
4. Java classes for implementing Javascript into Java program.

Rhino is initial a project started at Netscape in 1997. It is now a project host by Mozilla. If you are interested in the history, you can go to mozilla at http://www.mozilla.org/rhino/history.html.

The current version of Rhino is 1.7. The features of Rhino include:

1. Rhino supports the Implementation of Javascript 1.7,
2. Rhino supports the Implementation of ECMA 262, a general-purpose cross platform scripting language standard,
   
3. Rhino supports the Implementation of ECMA 357, xml scripting,
4. Rhino provides a Javascript Shell
5. Rhino provides a Javascript compiler
6. Rhino provides a Javascript Debugger
7. Rhino can be run on Apache Jakarta Bean Scripting Framework (BSF)