I’ll jot down some quick thoughts on Lemmy, a Reddit-like service for the Fediverse. When it first was announced a few years ago, I thought “yeah, right, it has a really long way to go” and instead of helping I just sorted it under “vaporware”. But now it’s becoming usable♥︎.
It’s centralized, and federated.
Every community is tightly tied to one server (while there are several servers, each have their own communities). So there’s not a lot you gain compared to something like a lobste.rs server or a Discourse server or a mailing list or other traditional forum softwares and bulletin boards. Each community is still centralized. (And you also get to keep some of the simplicity of that approach, but only some, because this is still Fedi in all its clunky glory.)
Unlike Discourse, you can post from an account from another server (sort of like with Open ID back in the blog era). This means from other Lemmy servers but also from other ActivityPub implementations. (It’s a “subset with extensions” so you might have to square peg it a bit.) You can also then receive replies and notifications on that home server, which is convenient and cozy. (On the other hand, some of these forum servers have mailing list modes which are convenient and cozy in their own way.)
It is also similar to Guppe in many ways. You can follow communities and it boosts posts from those communities into your timeline, and you can post to the community too. Compared to Guppe, there is moderation and group ownership, and there’s an optional Reddit-like web frontend. One way I like to use it is to browse the web frontend and then when I wanna reply, I dig up the post via Fedi and reply from there. A few extra hoops, but then I’ll see any replies from the comforts of my own home.
It’s basically a mailing list but Fedi instead of email.
Weird that I used Discourse as an example since they’re also planning to join the Fediverse / ActivityPub in the future.