The Virtual-Reality Peripheral Network (VRPN) is a set of classes within a
library and a set of servers that are designed to implement a
network-transparent interface between application programs and the set of
physical devices (tracker, etc.) used in a virtual-reality (VR) system.

The idea is to have a PC or other host at each VR station that controls the
peripherals (tracker, button device, haptic device, analog inputs, sound, etc).
VRPN provides connections between the application and all of the devices using
the appropriate class-of-service for each type of device sharing this link. The
application remains unaware of the network topology. Note that it is possible
to use VRPN with devices that are directly connected to the machine that the
application is running on, either using separate control programs or running
all as a single program.