I think thirsteh was talking about the big models that operate at the spreadsheet layer, without VBA. VBA is imperative, but when you chain worksheet functions together, you have a more explicit, more visible way of manipulating data the way you might with a functional programming language.

Indeed. Some people have even used e.g. Haskell to provide more "real" logic, but with Excel as the user interface:

http://qconlondon.com/london-2008/speaker/Lennart+Augustsson

http://urchin.earth.li/~ganesh/icfp08.pdf

These are cool! Thank you!