Dorsey has been hitting at that for a while but AFAIK never delivered.
Meanwhile some guys created Nostr[0] that is so simple and functional its comical. Basically you sign a message and broadcast to one or more relays. Its not even p2p.
Keet/Holepunch[1] are based on DHT and some bittorrenty things. Basically serverless and p2p as far as I can understand. There is some scrutiny about the source code not being available but they said the project is really nascent and as soon as they clean the code they'll release it. I'd like to see that.
Meanwhile some guys created Nostr[0] that is so simple and functional its comical. Basically you sign a message and broadcast to one or more relays. Its not even p2p.
Keet/Holepunch[1] are based on DHT and some bittorrenty things. Basically serverless and p2p as far as I can understand. There is some scrutiny about the source code not being available but they said the project is really nascent and as soon as they clean the code they'll release it. I'd like to see that.
[0] - https://nostr.com
[1] - https://keet.io
None of the above projects are blockchain based and require tokens to transact although they might have some LN integration in the future.