All updated mastodon instances use activitypub for federation between themselves and only use ostatus when federating to gnusocial instances. I'm not sure of the version where this switch happened, but instances not updated to that version would still use ostatus solely.
If I understand correctly activitypub is implemented by MediaGoblin....

My understanding is that:

    OStatus is a decentralized social networking protocol made up of several other protocols (Atom feeds, Activity Streams, PubSubHubbub, Salmon, and WebFinger)
        GNU Social and Mastodon are two server software applications that implement OStatus API is an interface to the server software (Activity Streams, OAuth, Web Host Metadata) is a instance (not accessible right now), GNU MediaGoblin is a server application that currently uses a pump-like API
    ActivityPub is a proposed decentralized social networking protocol
        GNU MediaGoblin is a server application that will likely implement ActivityPub

How do these protocols interoperate? Does ActivityPub completely replace OStatus, or only the Activity Streams component?
AFIAK Mediagoblin did have a GSOC 2017 goal for ActivityPub but it doesn't look like it was worked on as the Savanna git's federation branch was last committed to 22 months ago.

I've been hoping for some interaction with ActivityPub, but at least since they use PostgreSQL at the very least the database itself can store JSON in the same format ActivityPub sends
It's just a matter of someone coding it.
 my house near the sea,  
I don 't  completely understand  but you show for us also the #newhere from #diaspora?
I understand that we need a specific newhere here for hubzilla .
I saw at last 2 newhere from diaspora in my stream @cb7f604332cf39  
cc @New Here+
At least I do not need it
One thing I avoid is exactly this newhere of/from diaspora, I do not even care a little bit.
Forgive my sincerity, but after so many years of newhere from diaspora, my "chestnuts" are full.
I got that cause I've an abo to the #newhere tag in the diaspora plugin.
These contacts can't follow the New Here Forum, cause they are from Diaspora using Diaspora Protocol and not ZOT.
When you've got the diaspora plugin active you may add them as a new contact, otherwise take it as an hint how it works on Diaspora.
It was just an example and may be a little test to catch you ;-)
Don't want to bother you with tons of new here posts.
Inbetween I got 5 new post with newhere and don't forwarded them to all of my contacts.
  last edited: Sun, 14 Jan 2018 14:09:37 +0000  
This channel has no Diaspora contacts, but if you do, and use the newhere tag, then your public posts here will be visible in Diaspora, and I believe they will be able to comment as well. However this Forum was made to aid new Hubzilla members to join the community here. If they eventually want to add Diaspora contacts, they can do that later when they know their way around here.
 my house near the sea,  
With great sadness I discovered today that our friend Tony B. aka Tazman has left us.
My great adventure companion and friend in these 6/7 years of free foss networks.
Rest in peace my friend and find serenity in the other dimension <3 ... <3

Pink Floyd - " Breathe "
by HDPinkFloyd on YouTube

#libertree #redmatrix #hubzilla #friendica #gnusocial #diaspora
Riflessione: mia figlia parlando del significato della parola diaspora e del "sito" diaspora e chiedendo diaspora da cosa? E io cercando di spiegare che era la diaspora da facebook e affini l'idea sappiamo tutti che oltre al fatto che i creatori stessi continuavano e probabilmente continuano ad usare facebook anche un 90% degli attuali utenti continua ad usare facebook. #tristezza #diaspora :facepalm