A post at LWN.net announces the first alpha release of Jython 2.1.
"Jython is a Java implementation of the Python programming
language. It allows users to compile Python source code to
Java byte codes, and run the resulting bytecodes on any Java
Virtual Machine. It is a very seamless and smooth
integration with Java: from Python you have complete access
to all Java libraries, can build applets, can integrate with
Java beans, and can subclass Java classes in Python and vice
versa. Like Python, and unlike Java, Jython can also be
used interactively: just type some Jython code at the
prompt and see the results immediately."