1. A machine-implemented method for managing an operating system and applications, the machine-implemented method comprising: creating an instance of at least one data item for use by an application, the instance of the at least one data item having a respective data type, the respective data type defining compatible values for all instances of data items having a same type as the respective data type; determining whether the instance of the at least one data item has a dependent reference to an instance of at least one other data item; and preventing execution of the application when the instance of the at least one data item is determined to have the dependent reference and the instance of the at least one other data item is unresolved.