This is a group which uses ham radio frequencies to tie together a network of Raspberry PIs to create a wide area text/chat and remote control network without using Internet for data links. They use Internet for discussion, configuration, status reporting, but TARPN traffic is done via ham radio.
There is a local TARPN with 17 sites in Wendel, Knightdale, Raleigh, Cary, Chapel Hill, Durham, Hillsborough, Mebane.
TARPN has a web page (tarpn.net) and groups-io chat. The web page has a recipe and scripts for constructing network sites.
No dues, no club ownership of anything. There is a talk about TARPN given at the TriLug and made available by DataKraft on Youtube