The computer spreadsheet doesn't get enough credit among computer programmers. I think that more than any other one concept, VisiCalc, 1-2-3, and Excel were the killer app for the personal computer. As a programmer, I have tended first to think of formulae and calculation mechanisms when I think of spreadsheets, but the UI and development style are perhaps more significant. For each individual cell, you can look at the value, the formula, or the formatting, and change each through a menu. You can incrementally build up quite a complex application all on your own, never leaving the very environment you use to view the results. Why doesn't all software work this way, only better? That's what I'm working on. [Read More!]