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.