I'm very flattered Matt that you would offer to contribute your time :-)
The core source code is not open source I'm afraid as I'm hoping that it will be commercially viable, although it will be free and I won't do anything like introduce nasty advertising (my model are tools like Gmail and Quora).
However, it will be open in the sense that anyone will be able to contribute new functions, and if they are of sufficient quality they can be made available to anyone. In this way my hope is to create a collaborative community, much like with Quora or Wikipedia. I think, most likely, people's contributions will be under an open license.
I also intend to be very open in the sense of reaching out to users for feedback and suggestions, that being the purpose of this Google Group.
Sorry, I know that is probably not quite the answer you wanted to hear :-)
Ian.
I wouldn't mind doing some work for this, it seems interesting. If it is opensource, I can't find the repo anywhere.