Crunchy Frog is just a temporary name for this app. (Read the tutorial for more details.) What it does is to transform a "traditional" Python tutorial into an interactive session within your favourite web browser. Three modes of interaction are currently possible:
1. one-liner, similar to the typical instruction at the Python interpreter.
2. multi-line Python code, as entered in a traditional editor, and executed by Python.
3. Solutions to doctests, as described by Jeff Elkner in a post on edu-sig.
Crunchy Frog is more of a proof-of-concept than a serious application at this point. The code is rather messy, showing my total lack of experience with this type of program (web app). I will very likely rewrite it from scratch for the next release. To use it you will also need to have installed Elementtree (included with Python 2.5?) and CherryPy.
To try it: read the 5 (short) pages long "tutorial" included, using your favourite browser. Then, start Crunchy Frog, and go through the tutorial again. The whole thing should be doable in less than 10 minutes.