A multiple device management method and system that executes commands on one controller computer, such as in a data center, to initiate operations on controlled computers containing agent software. An operation may comprise the execution of script, execution of a binary program, or other operations. The mechanism works with sets of computers as if they were a single computer, whereby, for example, management of computing devices is greatly simplified, and the cost of managing computing devices in a data center is significantly reduced. The controller communicates with the nodes using a messaging format, and provides a schema to represent the available nodes in the data center, their organization into sets, and the results of ongoing and completed operations. The schema may also be used to manage jobs to perform on nodes and sets of nodes.