Discussion in W3C Social Web Incubator Community Group about this blog post and use of ActivityPub/ActivityStreams for groups: https://lists.w3.org/Archives/Public/public-swicg/2023Mar/0050.html
cel
Replying again just to note that the screenshot does not appear in Lemmy - and my edit saying so is not universally propogated (I see it in Friendica but not yet in Mastodon).
As I suppose Lemmy does not support the media attachment: Lemmy users can find the screenshot by navigating to Ваня's post at the linked original page (source) - or by viewing this thread on other non-Lemmy instances via other remote participants here (via the small fediverse icon links).
Cool, thanks Ваня!
Edit: the screenshot does not appear in Lemmy; I see it in Mastodon and Friendica.
I'm able to follow Lemmy accounts from Mastodon now. (Previously search was hanging, maybe the servers had to establish contact...)
Lemmy implements WebFinger (username@domain lookup) and "a subset of the ActivityPub Protocol, with some extensions" (https://join-lemmy.org/docs/en/federation/lemmy_protocol.html).
I was able to follow a Lemmy community from Mastodon. (I haven't seen what it looks like yet when posts start coming through.) I was not able to follow Lemmy communities from Epicyon, or Lemmy user accounts from either Mastodon or Epicyon.
Nice!
Mentioned to W3C SWICG in https://lists.w3.org/Archives/Public/public-swicg/2022Dec/0010.html (re: ActivityPub/Rust/Lemmy). More info about public-swicg
: https://lemmy.ml/post/630012
The list should be aware of this now (Group federation - referring to your comment @nutomic): https://lists.w3.org/Archives/Public/public-swicg/2023Mar/0074.html