Communication between application programs is facilitated by a virtual device driver to which the application programs make function calls. The device driver registers each application in response to a request for application-to-application communication. During registration, the device driver determines the addressing mode of the application being registered. An address mapping operation is performed and the results of the mapping operation along with other information about the application are stored in a data store administered by the kernel of the device driver. The device driver allows two applications of dissimilar addressing mode to communicate with one another without a priori knowledge of the communicating partner's addressing mode. The virtual device driver handles communication transparently for the communicating applications, allowing the applications to send and receive data.