1. A computer-readable medium or propagated signal having embodied thereon a computer program configured to generate data subscriptions, the medium or signal comprising one or more code segments configured to: access information identifying a type of data to be distributed to data sites; access information identifying a distribution criterion that defines the basis upon which the type of data is to be distributed to the data sites; access application data of various data types; and generate data subscriptions in a network of distributed computer systems operating an application program having the application data of the various data types, wherein each data subscription 1) is generated based on the type of data to be distributed to data sites and the distribution criterion and 2) identifies a portion of the application data to be distributed to one or more of the data sites.