@creweite: at the risk of posting some nonsense, this is how I understand things - I shall be glad to stand corrected.
FLARM is a technology developed in Central Europe for the specific purpose of collision avoidance among gliders (imagine them ridge soaring). It uses general purpose hardware, such as gps-receivers and 433/688 MHz transmitters, and seems to do a very good job for the given purpose, while remaining affordable AND modest on the power requirement - important in gliders!
FLARM seems to have especially good algorythms (sp?) for predicting potential collisions/conflicts.
Standard Flarm equipment gets information from a gps receiver (for the participants' own position and speed and altitude and direction/heading), broadcasts this, and receives the same info from other participants. Displays can show other traffic with the various parameters, and create alerts if a collision danger seems imminent.
"Power Flarm" I understand to do all the same things PLUS receive, interpret, and display data from ADS-B.