Meshtastic is an open source, off-grid, decentralized, mesh network built to run on affordable, low-power devices. A bit of history, a bit of the future and lots of hands-on action, running on the ISM and SRC frequencies below and above 1GHz. It uses Lora-P2P with dedicated radio chips and forms ad-hoc meshes. In HAM mode the encryption is switched off and the ISM airtime restrictions are lifted.