1. A method comprising: maintaining descriptions of a plurality of information technology resources in a computer-readable storage medium, wherein the descriptions indicate a set of one or more properties and settings of the set of one or more properties for the plurality of information technology resources, wherein at least a first of the set of one or more properties for each of the plurality of information technology resources is set to indicate at least one resource class that defines resource behavior; maintaining a plurality of evaluation strategies, wherein the evaluation strategies associate a plurality of rules with forms of changes to the plurality of information technology resources, wherein each of the plurality of rules comprises Boolean statement and an operation to perform based on outcome of the Boolean statement; responsive to detecting a command to change a first property of the set of properties of a first information technology resource of the plurality of information technology resources, determining that a first of the evaluation strategies associates at least one of the plurality of rules with a form of the change to the first property of the first information technology resource; evaluating the at least one of the plurality of rules; and performing the operation of the at least one rule.