Free Internetworking Peering System and mesh routing protocol

It's a mesh based on spanning-tree protocol, with single, global root based on smallest random generated address. Each node has single global "depth" (determined by connectivity) and nodes with smaller depth get to route higher proportion of the traffic.

The choice of spanning tree is an interesting one - as it makes some nodes more important than others. Based on the description, I'd expect something more decentralized, like a DHT.