Not really relevant to an Apple environment. But I created a reasonably complex RAD/front office tool in a bank. Using spreadsheets as the format for all user i

Not really relevant to an Apple environment. But I created a reasonably complex RAD/front office tool in a bank. Using spreadsheets as the format for all user inputs was phenomenally efficient for users are there was lot of tabular data (mappings, time series, trade lists, etc), and even a semi-sophisticated excel user will edit excel files extremely quickly. Wasn't python, it was C#+SpreadsheetGear (great commercial library for spreadsheets manipulations).