1. One or more tangible computer-readable storage devices having computer-readable instructions stored therein that, when executed by a computing device, cause the computing device to perform acts comprising: receiving a set of one or more constraints for Open Packaging Convention (OPC) package validation; receiving constraint grammar, the constraint grammar including application-specific limitations on OPC packages; comparing the set of one or more constraints with the constraint grammar to determine whether the set of one or more constraints conforms to the constraint grammar; receiving a package; identifying one or more parts of the package, wherein each part of the one or more parts is reachable by a chain of relationships; determining, without user interaction, whether the one or more parts and their relationships conform to the set of one or more constraints; and if any of the one or more parts or their relationships do not conform to the set of one or more constraints, providing data identifying the one or more parts or their relationships that do not conform to the set of one or more constraints; and if the one or more parts and their relationships conform to the set of one or more constraints, distributing the package to one or more computing applications.