I've been using Cjdns. It provides (cryptoauthenticated) IP6, so nostr, email, matrix, bitcoin, etc are accessible just by running a node. It runs on layer 2 or UDP.
Similar projects are yggdrasil and pinecone.
Discussion
Yes, it's pretty cool too. Problem is overhead for things like LoRa.
Reticulum also provides physical layer firmware for LoRa, so you can flash 20$ device and that will provide you a radio link.