The Fediverse is a massive place with many different software platforms that have different goals but share their support of the ActivityPub protocol.
Twitter Clone
- mastodon
- pleroma
- soapbox
Youtube Clone
- peertube
Instagram Clone
- pixelfed
Facebook Clone -Friendica
Blogging Platforms
- writefreely
- wordpress
Book sites
- bookwyrm
Music sites
- funkwhale
and if you’re really stretching the definition then perhaps chat services like matrix (though matrix doesn’t use activitypub).
According to one of my favorite sources on the matter, https://the-federation.info/ the fediverse has about 2M active users.
The “threadiverse” consists mostly of the reddit clones. It includes lemmy and kbin, and in more limited extents lotide (It fits the bill but has challenges with federation) and parts of friendica as well as possibly a.gup.pe.
This is just a small taste of all the different projects out there. For a lot of people they might not like one thing but they might like others. Decentralization is strength on the fediverse.
Yeah, good that you guys are making such lists. It took me a few days to truly understand the “threadiverse” but now, as in right now, I am stumped trying to understand how does everyone integrate with Mastodon (which I understand to be not-Twitter) and then what do all of the other platforms even do! What is Misskey and how is it different from Calckey or Akkoma or Friendica… And how do they interact between each other. I am very confused but also very excited.