A standard reporting schema to represent applications and other information on a computer in a hierarchical manner, such as via an XML (extensible markup language) file. An agent or engine is provided to inventory a computer for installed applications or services and to output a report, or log file, conforming to the schema standard. A calculation may be performed on a subset of attributes stored in the log file for an application or a service so as generate a signature representing the subset. The signature may be stored with the log file, and may be accessed quickly in a database to determine whether or not the application is a particular application, or, if more particular resources are defined, to determine more specific information, such as whether the application is a particular version or run of the application.