Could you elaborate why? I imagine not many people are familiar with Soup.
Chapter 11 of the Newton Programmers Guide[1] gives a fairly detailed description with pictures. Relational Databases are nice, but I would rather deal in objects (well frames).
This sounds really intriguing, do you know of any open source implementations for other operating systems/programming languages?
I haven't found just a soup implementation (would be interesting for javascript given the prototype objects). NEWT/0[1] is a full NewtoScript but it looks unused.