Abstract: A rules editor for creating rules for a software application. The editor is suitable for running on a computing device having at least a processor, a memory, a display device and an input device. The editor includes a graphical editor for: retrieving from the memory and displaying on the display device one or more graphical icons; and enabling a user to select and arrange at least some of the icons on the display device using the input device so as to form a graphical representation of a rule to be processed by the software application. The editor includes a spreadsheet editor for displaying on the display device one or more spreadsheets forming a spreadsheet representation of rules to be processed by the software application, and enabling the user to edit the spreadsheet representation.