DisasterRadio is an off grid (solar powered) low bandwidth long range mesh network.
Nodes currently use the LoRa PHY (CSS modulation) to communicate between each-other, and WiFi to communicate with client devices.
Web apps like chat / microblogging are served up over the wifi connection, requiring only a client device with wifi and a web browser to use.
Code is here: https://github.com/sudomesh/disaster-radio-nodemcu
Status as of June 10th 2017: Basic chat between two nodes working.