Minds just launched ActivityPub support (fediverse).

X is showing no signs of decentralizing and open sourcing. In fact that they are punishing outside links.

Threads and Tumblr are poised to release ActivityPub support. EU is forcing Instagram to do it.

Mastodon is the largest ActivityPub implementation but has a deeply divided culture.

Truth and Gab have intentionally defederated from ActivityPub and don't seem interested in decentralization despite forking it.

Bluesky (ATP) federation is not out of sandbox and is very limited.

Farcaster, Friend tech and Lens are still very niche Ethereum communities.

What else?