I will not federate with any meta products

Replied in another comment, but here is is again. https://fedipact.veganism.social/

I don't know, but you can check individual instances by going to the /instances subdomain and searching for threads.

shjw and blahaj are defederated, world isn't.
This can always change, but I have confidence in my admins.

Edit: Thanks to Canyon201@lemmy.world for this link

And now I'm commenting from a lemmy.world account because Lemmy from Mastodon has some rough edges like the need to tag the community in my comment above to ensure it actually reaches the lemmy.world server.

Tumblr and Flickr are also talking about ActivityPub support, but it's not clear if or when that will actually happen. It would make more sense to me for those services since they're fairly small and it's a way to substantially increase the possible audience. It's not clear what Meta's motivations are here, though a motivation some have proposed is that they're trying to get in front of potential regulation. The EU Digital Markets Act, for example requires some services to interoperate with competitors, and having one of its new products join an established standard protocol is a way to say "you don't need to regulate us, we already do the thing".

I don't think their blocking of comments mentioning Pixelfed is intentional. Pixelfed is not popular enough for Meta to care about as a competitor, and blocking mentions of competitors has never been among their tactics.

You need more training in corporate risk management, grasshopper! AP/AtProto isn't a revenue opportunity, it's a potential front for which they'll need to have a battle-ready product and brand. Ever heard the saying 'engagement is containment'?

Always has. Anything using ActivittPub can interoperate

@LibertyLizard @technology It always has. They both speak ActivityPub.

The UX can be awkward though. As an example, I had to add the community tag to this comment manually, as it won't federate to lemmy.world otherwise. That's because Mastodon doesn't push replies to every server with users participating in a thread, which I think is a design flaw.

To post to Lemmy from Mastodon, just tag a community. You can load any of the fediverse links shown in the default Lemmy web UI in a Mastodon search box and reply to them. You can also follow a community and receive every subsequent post and comment as a boost (this is a bad UX and I don't recommend it), as well as follow Lemmy users, which you can't do in Lemmy itself. You cannot vote on Lemmy posts/comments from Mastodon.

I find tagging an appropriate Lemmy community from my Mastodon posts to be a good experience. You'll see a few of those from my @zaktakespictures account in @birding, and from @zakreviews in @flashlight.

I'm pretty sure Lemmy won't make new toplevel posts out of this in those communities since it's a reply, but I'm going to check just to be sure.