I've been happily using Jython for a while now, and now I'm getting this nagging feeling that I want to understand how Jython works under the hood. Both to satisfy my curiosity and to get a better understanding of Jython. Unfortunately I can't find much online material to enlighten me. Is there a source where I can get answers to questions such as:

- How does Jython work? What does it exactly do to get from java to python and vice versa?
- What are the major difficulties in implementing Jython?
- What is the ratio java/python code?
- ...

Thanks! And keep up the good work.