The goal of modularity is to obtain code that is easily read and modified. For CHAMMP this is particularly important for the addition of new or modified physics. The need for standardized interfaces has been recognized for some time. In particular see, [Pielke, R.A. and Arrit, R.W., (1984) "A proposal to standardize models" in Bull. Am. Met. Soc. 65: 1082]