ActivityPub everywhere?

By Johannes Ernst


In previous posts, I argued the EU’s Digital Services and Digital Markets Acts are the most likely reason why Meta is implementing ActivityPub in its upcoming Twitter competitor “P92”, and that ActivityPub is really the only game in town that meets Meta’s requirements for interop for “P92”, as they require protocols that are proven to work and governed in a lawyer-vetted process by a legitimate standards organization.

But if that line of reasoning is correct for for why Meta would pick ActivityPub to meet its interoperability obligations under EU’s new rules, it is likely also correct for all other social networking products, by Meta and others, that are required to interop by the same new rules, notably:

  • Facebook (also Meta)
  • Instagram (also Meta)
  • Snapchat (Snap)
  • LinkedIn (Microsoft)
  • Twitter
  • and perhaps even YouTube (Google).

(The full list is here although I think the EU puts them in different markets. Update 2023-06-30: Actually, this is the wrong list; the list of “gatekeepers” will only be established in a couple of months under the Digital Markets Act. Chances are it’s very similar to this list of “Very large on-line platforms”, however.)

Let me say this again. The product teams of all of those products are very likely asking themselves the very same question right now that Meta asked itself: what are we going to implement to meet our interop obligations, and when are we going to do it?

I believe most will arrive at the same conclusion: they will look for protocols that can demonstrably work for these kinds of interop requirements, and that are maintained by a well-understood standards organization. And will find that ActivityPub is the only game in town that meets those requirements.

(It is possible that one or two of the organizations above come up with a “spoiler” strategy developing or picking an alternate protocol. To make up a random example, say, Microsoft might buy Bluesky and declare it to be its interop architecture. They would have to turn that protocol over to a standards org, however, before its competitors would even consider it. And that might not gain them much; sticking with ActivityPub is simpler.)

(It is also possible that some of the above organization will choose to fight the EU in court; Twitter comes to mind. I’m not a lawyer, I don’t know how likely this might succeed; however, the EU has shown to be tenacious and unstoppably moving forward in this direction, so I wouldn’t bet on that strategy if I were them.)

Which means a number of things – starting with the ActivityPub standardization process in the W3C:

  • Meta, Microsoft and others will suddenly show up in the W3C ActivityPub community. It’s easy for them to do, they already have been spending significant amounts of time in the W3C.

  • They will show up with requirements currently considered out of scope by the W3C SWICG, but driven by the need that the entire stack is standardized that is necessary to enable interop between, say LinkedIn and Facebook. If they decide that real interop is actually necessary – my premise – then an “assembly required” standard (like ActivityPub is today) is not sufficient for them.

  • Therefore the official Social Web Working Group will need to be re-constituted, and its charter will need to be broader than it was before.

  • There will be loud screaming in the existing W3C social community. (Because many of the members of the current SWIGC are extremely strongly in opposed to surveillance capitalism – the prevailing business model of most of the companies above – or, in some cases, that any kind of business has any role in desirable forms of social media at all.) An accommodation will have to be found, as the W3C as an organization wants to serve all willing participants in a standards process, not just those with a certain value system.

But there more intriguing, and exciting possibility is this:

  • When everything is said and done and my line of reasoning is reasonably correct, interoperability via ActivityPub indeed might be “everywhere”: Facebook, Instagram, P92, LinkedIn, Snapchat, even Twitter.

Social media would end up being a radically different beast. A potentially much better, beast as I believe. Ponder this.

Updated 2023-06-30:

  • Added Digital Markets Act in addition to the Digital Services Act; it’s really both and the intent behind them that drive this.