Viva - Open Source Languages for the Java Runtime

Jython (Python for Java)
http://www.jython.org | http://sourceforge.net/projects/jython
Jython is a 100 % Java version of the Python scripting language that allows you to compile Python scripts to Java byte code that runs on any Java Virtual Machine. Jython offers seamless and smoth Java intergration: from Python you can access all Java libraries, you can build applets or Java beans, you can derive from Java classes in Python and vice versa. Like Python, and unlike Java, you can use Jython interactively: just type in some Jython code at the prompt and see the story unfold immediately; licensed under an Apache-style license; headed by Finn Bock

Groovy
http://groovy.codehaus.org | http://wiki.codehaus.org/groovy
Groovy is a free, open-source scripting language in Java for the Java runtime that borrows the best from dynamic languages like Python, Ruby and Smalltalk and offers it to you in a all-in-one package using a Java-style syntax. Note, you can also use Groovy as an alternative compiler to javac to create standard Java bytecode; licensed under an Apache-style license; headed by James Strachan and Bob McWhirter

Java Lite/Dynamic Java - BeanShell (bsh)
http://www.beanshell.org | http://sourceforge.net/projects/beanshell
BeanShell (bsh) is a free, open-source, small (~175k) scripting interpreter in 100 % Java that runs standard Java statements and expressions and also sports a dynamically typed, casting optional Java lite syntax; licensed under GNU Library GPL (LGPL); headed by Patrick Niemeyer.

Tcl - Jacl (Java Command Language)
http://tcljava.sourceforge.net | http://sourceforge.net/projects/tcljava | http://www.tcl.tk/software/java
Jacl is a free, open-source Tcl 8.x scripting interpreter in 100 % Java initially created by Sun Labs in 1998 and now headed Mo DeJong; licensed under a BSD license; Jon Ousterhout created Tcl in the late 80's as an embeddable command language for interactive Unix tools.

JavacScript - Rhino
http://www.mozilla.org/rhino
Rhino is a free, open-source Mozilla-licensed Javascript engine in Java. Netscape started work on Rhino in Fall 1997 for the now defunct "Javagator".

Ruby - JRuby
http://jruby.sourceforge.net | http://sourceforge.net/projects/jruby
JRuby is a free, open-source Ruby interpreter in Java that you can easily add to your app to script any Java class.

Smalltalk - Bistro
http://bistro.sourceforge.net | http://sourceforge.net/projects/bistro
Bistro is a free, open-source variant of Smalltalk in Java than runs on any Java Virtual Machine. Bistro mixes the best of Smalltalk and Java.

Lisp/Scheme - Kawa, JScheme
http://www.gnu.org/software/kawa
KaWa is a Scheme interpreter in Java; licensed under the GNU GPL; headed by Per Bothner; (Scheme is a modern variant of Lisp.)
http://jscheme.sourceforge.net | http://sourceforge.net/projects/jscheme
JScheme is a Scheme interpreter in Java; licensed under an Apache-style license; headed by Ken Anderson, Tim Hickey and Peter Norvig

Robert Tolksdorf's Programming Languages for the Java Virtual Machine Directory
http://www.robert-tolksdorf.de/vmlanguages