RFX is a software module that facilitates TCP/IP communication between a robot and a controlling (or observing) client. Unlike node-based messaging architectures used in large modular systems (for example, ROS and Orocos RTT, where the observer would attach to the common communication channel between the task controller and sensors/actuators), RFX is a communication model with only two end points. The task controller on the robot sets up the RFX communication service and waits for a client to connect. RFX is specifically designed for connecting to the task controller of a small robot and receiving a video stream that originates from the on-board camera.
RFX is a research project. The advantages of RFX over a third-party robot communication solution are not clear at the moment. The narrow focus of RFX should result in a more efficient message transport layer but the implementation details will play a bigger role in determining that.