Back to @captaincalliope.blue's original pointsin this thread:

I want a new flagship #atproto app that isn't a Twitter clone on the surface.

Indeed -- Rudy Fraser talked a lot about this in his ATmosphereConf presentation. And the same is true here in fedi, where Mastodon is still dominant. I think of this in a couple dimensions

• getting beyond microblogging, but still skeumorphic to well-known centralized systems (Pixelfed and Lemmy here; Flashes, Skylight, and Streamplace in the ATmosphere). If done well, that's valiuable in terms of getting people to the ecosystem (from an activism perspective, the lack of a skeumorphic approximation to Facebook groups is a huge barrier) but my guess this is still likely to have somewhat limited impact. When was the last time when a better skeumorphic app ever really caught on and displaced an incumbent>

• less-skeumorphic software is where it really gets exciting. There's a lot of momentum here -- Bonfire, Bandwagon, Piefed are three good examples here in fedi, the stuff Blacksky is working in the ATmosphere -- but it's very hard to predict what will and won't catch on.

"I also want to see #activitypub get some of the primitives that #atproto has such as decentralized identifiers (except for real), personal data stores, content addresses, etc.

I want to see both protocols cross-pollinate with each other's strengths. And perhaps share infrastructure like identities."

Yeah, totally agree. I think t here's been some cross-pollination in both directions (Blacksky's local-only posts were directly inspired by Hometown, Mastodon's FASP and Fedisovery are somewhat influenced by AT's Relay-based architecture) but there's certainly a lot of room for improvement.

curious how you imagine adding did-style identities + personal data stores to activitypub without breaking existing servers/clients – do you see it as an extension layer (like webfinger 2.0) or a more radical protocol rev?

Your analysis is very accurate and objectively correct.. However, there is an analogy that is not entirely relevant.

thenexusofprivacy@infosec.exchange said in I also want to see #activitypub get some of the primitives that #atproto has such as decentralized identifiers (except for real), personal data stores, content addresses, etc.:
> Bluesky's role in the ATmosphere is somewhat analogous to Mastodon's in the Fediverse back in 2022: it's the biggest and best-known app, and gets almost all the press, but isn't the main source of innovation.

In fact, 2022 doesn't correspond so precisely with the year 2025 for Bluesky.
Mastodon was six years old in 2022, and in those six years it gained its leadership by competing with equally structured or even much more structured alternative platforms like diaspora*, Friendica, Misskey, and, more recently, Lemmy, who proposed a different interaction model.
Throughout that period, Mastodon was never considered a leader by its "competitors," and often not even a point of reference.
This led to an evolution of the Fediverse ecosystem that was much more influenced by natural selection, and thanks to this natural selection and also thanks to the many dead branches, there is so much diversity.

I'm fairly certain that this diversity is the fundamental asset of the Fediverse, and that this asset will hardly ever be possessed by the Bluesky ecosystem.

Agreed that Mastodon 2022 / Bluesky 2025 is far from a precise correspondence! But while fedi's ecosystem is very diverse in some ways (and I agree that's a fundamental asset), it's much less diverse in others. Similarly the ATmosphere ecosystem is very diverse in some ways.but much less diverse in others. So my guess is that most fedi projects have an analogue in the ATmosphere -- not as far along because it's newer, and we'll see how many continue and how many wind up as dead ends.

Of course there are plenty of exceptions. Off the top of my head, I can't think of ATmosphere analogies of Bonfire, Frequency, or the friendica/Hubzilla/(streams)/Forte family. Then again there are also ATmosphere projects where I can't think of any fedi analogy: Blacksky, Gerrm, XBlock labeler, Anisota, Semble (a sense-making app). And some of the ways the ecosystems aren't diverse mirror each other; for example both are very Europe/US/Canada-centric.

@informapirata

thenexusofprivacy@infosec.exchange said:
> less-skeumorphic software is where it really gets exciting.

Another great but just-launched example of this is Sidetrail, which is for taking a journey through some content: https://sidetrail.app/

It uses AT Protocol, but isn't microblogging, isn't photo sharing, isn't forums or link aggregation, isn't blogging, etc. It's something entirely new.

informapirata if you ask any ActivityPub software author about Mastodon's role in ActivityPub and standardisation, then you'll often see that ActivityPub software authors end up having to build for compatibility with Mastodon. There are certain quirks of Mastodon's specific implementation of ActivityPub that cause certain problems (I won't enumerate them here), but a very common trend right now is to see protocol implementation by lowest common denominator (i.e., compatibility with the largest application). Take for instance a new Music scrobbling service developer I was chatting with a few weeks ago, I asked him if he was going to use the Listen activity to federate out listens. His answer? No, I'm going to use Note so that people on Mastodon can follow what I'm listening to.

Another example of this, Pixelfed and Loops. Take a guess what object type they both federate out. Is it Image or Video? Nope. It's not. It's Note, once again for compatibility with Mastodon. See: https://blog.joinloops.org/loops-joins-the-fediverse/ (heading "Smart Content Representation")

Another fun fact: We all know that we use the @username@server.example syntax for mentioning people on the Fediverse. Take a guess where that is defined? I'll wait. Hint: It's not ActivityPub. That was Mastodon. Mastodon chose twitter style handles and used Webfinger to implement them. Webfinger is not actually part of the activitypub or social web specifications, it's completely separate. We have since had to write a document explaining all the quirky weird things needed to implement webfinger with ActivityPub, but it's inherently not part of ActivityPub: https://swicg.github.io/activitypub-webfinger/

(I also learned that ActivityPub does not actually have a real concept of "usernames" recently in: https://hachyderm.io/[thisismissem](/user/thisismissem%40activitypub.space)/115401128778866273 )

So is ActivityPub and Fediverse really not just controlled by the whims of Mastodon and Mastodon's legacy as the largest service in the Fediverse?

Also, technically the Decentralized Identifiers work is compatible with Actors in ActivityStreams 2.0, and that was a deliberate choice. Both use the alsoKnownAs property, and they use the same or an earlier version of the same security context in JSON-LD, and that was, I'm told, a deliberate design decision.

@oxpsi I don't think either require a radical protocol rev. ActivityPods already uses Solid as the personal data store, and as @thisismissem pointed out broad adoption of ActivityPub C2S (perhaps with some improvements) would move things in a very PDS-like direction. Similarly for identity Forte and Mitra

For identity there are various implementations within ActivityPub that separate identity from the hosting instance. And as @thisismissem says elsewhere in this thread

"Also, technically the Decentralized Identifiers work is compatible with Actors in ActivityStreams 2.0, and that was a deliberate choice. Both use the alsoKnownAs property, and they use the same or an earlier version of the same security context in JSON-LD, and that was, I'm told, a deliberate design decision."

@thenexusofprivacy @oxpsi I've also quietly been working on a research project to explore exactly this topic, and figure out ways to be compatible whilst different.

thisismissem Let's say I'm very influenced by the fact that I started my instance administration journey with a Friendica server, later joined by a Lemmy server.

The Friendica and Lemmy developers have never been subservient to Mastodon.

And while the Friendica developers have always claimed a specific mission, which is to always seek maximum compatibility and connectivity with other systems, the Lemmy developers have always asserted their independence from Mastodon's solutions.

For the rest, you're right about the de facto dictatorship that Mastodon often exerts, especially over "younger" developers, but it's not a real form of control.

Furthermore, things are changing faster than they seem, thanks to the evolution of two platforms: WordPress on one hand and the one we're talking about now on the other.

Right, but to my knowledge both Lemmy and Friendica both use Webfinger (not sure when Friendica implemented this whether before / after Mastodon), but still, there's a lot of stuff in the fediverse that is down to Mastodon's implementation, rather than anything else.

My only bug bear with Lemmy is that communities and users are not distinct actors. Why not setup a community.server.example subdomain and server community actors from that instead of the main domain? Then you could reliably address communities from all software.