I am greatly interested in how one can best develop mathematical applications so as to produce clarity of presentation and maximal functionality with ease of use. I have been influenced by the works of Edward R. Tufte on data graphics: The Visual Display of Quantitative Information, Envisioning Information, and Visual Explanations.
With Mathematica notebooks we have an active and dynamic medium of expression and an added task of also presenting mathematical and dynamic concepts and not just data. This is an entirely new enterprise. We have to learn how to use the new capabilities and design presentations that are clear and elegant. We must combine mathematics, art and taste to write literate technical documents.
One of the applications I’m working on with John Browne is Grassmann Calculus. It is still in beta testing development and can be obtained free from the Grassmann Calculus page.