@cwebber Indeed you and others involved with AP spec development have been very inclusive, inviting and encouraging. I very much appreciate your (and everyone else's) efforts that have been put into #ActivityPub.
@cwebber The only reason !GNUsocial doesn't have #ActivityPub yet is because I have a fulltime job and noone else has been up for the task .]
Though I'm pretty sure it'd still just be the 100% public parts of AP that would be used/promoted, as I'm pretty much convinced there's no such thing as privacy in the social sphere anyway and anyone using "private" communication in an environment like !GNUsocial or #Mastodon is fooled either by the platform, the administrator or other users. (anything accessible via a web browser isn't made for privacy)
@sonyampump.io has private messaging, followers-only posting, federated identity so you can run around on other servers and comment using your home id, the API is lightweight and very consistent and understandable in comparison with GS+Qvitter (I hear), and it's the basis for the Next Big Thing, #activitypub.
pump.io was built in a few months by one guy though, and GS was built in a couple of years by several full-time people, so there are still quirks in the (actually intentionally) limited web UI. pump.io works best with a client.
@andstatus does a decent job. I'm not going to complain, because I still didn't file those bugs since last I complained, so the buck is with me. It's mostly about message formatting, other than that it's an awesome client for both GS and pump.