1. A computer program product for managing a plurality of information technology resources, the computer program product comprising: a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code configured to, maintain descriptions of the 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 is associated with a plurality of rules and defines resource behavior; maintain a plurality of evaluation strategies, wherein the evaluation strategies include associations of command patterns, that are determined to match respective sets of commands to be processed, with the 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; and responsive to detection of a received command to change a first property of the set of properties of a first information technology resource of the plurality of information technology resources, select a subset of rules based on an evaluation strategy in accordance with one or more of the command patterns that match the received command, wherein each rule of the subset of rules comprises a determined priority and bindings to variables associated with the command patterns, rank each rule in the subset of rules to determine an order of execution based upon each rules determined priority and the variables associated with the command patterns, evaluate a rule of the subset of rules, based on the ranked order of execution, update evaluation strategy information associated with the evaluation strategy, wherein the rule evaluated may create a generated command to make another change to the first information technology resource; and perform the operation of the rule.