1. A computer implemented method of preparing an executable representation of a rating model, the method comprising: defining an actuary-manipulable representation of a rating model, the actuary-manipulable representation embodied in computer readable media and encoding therein variables, factor tables and calculation sequences of the rating model, the factor tables having one or more axes bound to respective ones of the variables and the calculation sequences defined in terms of steps operative on values of the variables and cells of the factor tables; and transforming the actuary-manipulable representation to the executable representation, the executable representation embodied in computer readable media and encoding therein resultant computer program code including a runtime lookup facility for identification of runtime identifiers in the executable representation corresponding to ones of the variables and a calculate method executable to generate a quote based on inputs supplied via a predefined input interface, wherein the transforming is performed at least in part by a compiler that executes on a computational machine.