1. A data processing system comprising: one or more repositories, each repository containing one or more spreadsheet module definitions, and each spreadsheet module definition comprising module definition software code specifying one or more spreadsheet objects; a computer software application or linked library used by a computing device having an operational memory, the computer software application or linked library acting as a module factory that executes module definition software code associated with the one or more spreadsheet module definitions to create a spreadsheet workbook and provides the created spreadsheet workbook in the operational memory of the computing device; and a spreadsheet engine used by the computing device into which the spreadsheet workbook is loaded after creation and which manages and executes the spreadsheet workbook; the data processing system thus providing a runtime dynamically generated spreadsheet workbook.