To maximize the number of different client languages that can use the OpenROAD Application Server, all server facilities are accessed through COM Automation-compatible interfaces. This means that parameters passed to the remote 4GL procedures must be expressed within the set of datatypes supported by COM Automation.

This common denominator provides a rich collection of types, but does not include all the object types (such as system classes) that an OpenROAD procedure might accept as parameters in a purely OpenROAD context. When an OpenROAD client makes a remote call to an OpenROAD server procedure, the parameter types that can be passed are limited to the set of types that can be converted to and from COM Automation types.

The primary goal of the OpenROAD Application Server is to allow many different client languages to share the same OpenROAD 4GL business logic. It does not (at this time) provide transparent partitioning of OpenROAD applications. Remote 4GL procedure calls are limited to the common denominator of Automation parameter types, and therefore cannot duplicate all the functionality of purely local OpenROAD 4GL procedure calls.