Rhino is a JavaScript engine developed entirely in Java and managed by the Mozilla Foundation as open source software. It is separate from the SpiderMonkey engine, which is also developed by Mozilla, but is written in C++ and is used in Mozilla Firefox.
== History ==
The Rhino project was started at Netscape in 1997. At the time, Netscape was planning to produce a version of Netscape Navigator written fully in Java and so it needed an implementation of JavaScript written in Java. When Netscape stopped work on "Javagator", as it was called, the Rhino project was finished as a JavaScript engine....