I remember this being a kinda niche alternative to activity pub, and I always liked it because it had the ability to be local and P2P, with federated instances really just being repeaters. I didn’t like that it was immutable, but that was just the cost. Also you had to install something, which made it not as simple as just browser stuff. I see on Google there are SS to ActivityPub adapters too.
That’s not quite right. It’s hard to wrap your mind around. Basically every person in the network is a router for the entire network, kinda like the blockchain. You keep a microblog, and it just gets passed around like a trading card to all other people P2P. Unlike matrix, it’s not chat, it’s publishing.