ActivityPub, the IndieWeb, and the federation recovery
The platform decade absorbed federated social communication into a small number of centralized social networks. The recovery of federation, treated in this chapter, is the most visible of the recoveries in Part V because it has, in the last few years, begun to acquire user numbers in the millions rather than thousands and has, in some specific moments, played a role in the broader public’s understanding of what the alternative to the platforms could look like. The two principal strands of the federation recovery are ActivityPub, the W3C Recommendation that has produced the fediverse, and the IndieWeb, a smaller movement that has been working since around 2010 on personal-site-based alternatives to the platforms. A third strand, less visible than the first two but growing, includes the alternative protocols (AT Protocol behind Bluesky; Nostr; various others) that propose different technical foundations for federated social communication. This chapter takes the three strands in turn, describes what has been recovered, names what is still hard, and tries to be honest about the state of the recovery in 2026.
ActivityPub
ActivityPub became a W3C Recommendation on January 23, 2018. The principal authors were Christopher Lemmer Webber, Jessica Tallon, Erin Shepherd, Amy Guy, and Evan Prodromou. The standard descended from a lineage of social-network protocols that had been in development for over a decade. Evan Prodromou had been working on federated social networks since around 2008, when he founded the company Status.Net (later renamed Identica) and built a federated microblogging service called identi.ca on a protocol he called OStatus. OStatus combined several existing protocols (Atom for content syndication, PubSubHubbub for real-time notification, Salmon for cross-server replies, and others) into a working federation specification. Identica peaked at perhaps 50,000 users and operated as a federation peer for several years before Prodromou shut it down. The OStatus stack was, in its time, the most-elaborated working specification for federated social networking, and it provided a substantial part of the technical and conceptual foundation that ActivityPub built on.
ActivityPub itself rests on ActivityStreams 2.0, a W3C standard for representing social-network activities — posts, replies, follows, likes, shares — as structured JSON objects. ActivityPub specifies, on top of ActivityStreams, how servers should exchange these activities: each user has an inbox (where activities directed at them arrive) and an outbox (where activities they generate are placed for delivery), and the protocol describes how servers should push activities between users’ boxes and how clients should interact with the boxes. The design is decentralized: any server implementing the protocol can interoperate with any other, and users on one server can follow, reply to, and interact with users on any other server they can reach.
The technical design has well-understood limitations. ActivityPub does not include search across the federation, which means that finding people and content is harder than on centralized platforms. ActivityPub does not include strong identity guarantees, which means that account portability between servers is, in practice, fragile (you can move an account, but the move is not seamless and not all servers support it equally). ActivityPub does not include payment, dispute resolution, or any of the various non-technical scaffolding that platforms provide. The protocol is, by design, a thin specification of how messages flow between servers, with the rest of the social-network experience built on top by individual servers and clients.
Mastodon and the fediverse
The application that has made ActivityPub visible to a broad audience is Mastodon, created by Eugen Rochko, a German software developer, beginning in 2016. The first release was in March 2016, with a small initial user base that grew steadily through the late 2010s. Mastodon is, in functional terms, a microblogging service modeled on Twitter: short posts, profile pages, replies, boosts (the Mastodon equivalent of retweets), favorites, and direct messaging. The architectural difference is that Mastodon is federated: any organization or individual can run their own Mastodon server (called an “instance”), with their own users, their own moderation policies, their own community, and their own continued existence under their own control. Users on different Mastodon instances can follow, reply to, and interact with each other through ActivityPub, with the experience approximating what a centralized social network would provide.
Mastodon’s growth has been uneven. The user base was, through 2017-2021, in the low hundreds of thousands, with periodic small surges in response to controversies at the centralized platforms. The major inflection came in October 2022, when Elon Musk acquired Twitter and began making changes that produced widespread dissatisfaction among Twitter’s user base. Several million Twitter users registered Mastodon accounts in the weeks and months that followed. The Mastodon network, which had been operating at a few hundred thousand monthly active users, grew to several million monthly active users in late 2022 and into 2023. The growth has been uneven since then: many of the post-Twitter arrivals did not stick with Mastodon, but the user base has stabilized at a substantially higher level than before the surge, with estimates in 2026 of monthly active fediverse users in the range of one to three million.
The fediverse — the broader network of ActivityPub-implementing services — extends beyond Mastodon. Pleroma, a Mastodon-compatible service with a lighter implementation, has a substantial user base. PixelFed provides an Instagram-like photo-sharing service over ActivityPub. PeerTube provides a YouTube-like video service. WriteFreely provides blog hosting. Lemmy provides a Reddit-like community-based discussion service. Misskey, a Japanese ActivityPub implementation with a distinctive feature set, has a substantial Asian user base. Each of these services interoperates, through ActivityPub, with the others; a Mastodon user can follow a PixelFed account, a Lemmy community can be subscribed to from Mastodon, and the federation graph is, in principle, unified.
The structural achievement of the fediverse is real. It is, in 2026, the largest federated social network that has existed since Usenet. The number of operating instances is in the tens of thousands. The number of monthly active users across all services is in the millions. The protocol is open, the implementations are open-source, the moderation policies are determined by each instance’s operators, and the federation is genuinely federated in the way that Usenet was: no single party controls it. The recovery is not complete — the user base is small compared to the centralized platforms, the user experience is in many respects rougher, and many features that platform users expect are missing — but the recovery is real.
What the fediverse gets right
The fediverse, as a social-network experience, has several properties that the centralized platforms have lost or never had.
The user’s relationship to moderation is direct. Each instance is moderated by its operators, with whatever policies the operators have set. Users who don’t like an instance’s moderation can move to another instance. Users on an instance whose moderation they trust can have a meaningful relationship with the moderation team in a way that is impossible on a centralized platform with hundreds of millions of users. The result is, for many fediverse users, a more humane and more accountable moderation experience than the platforms have been able to provide.
The user’s data is, in a meaningful sense, the user’s. A fediverse user can export their data from their instance and import it to another. The export-import process is not as seamless as it should be (account portability remains, as noted above, fragile), but it is structurally possible in a way that platform exports are not. A user who is dissatisfied with their instance can leave with substantial portions of their history intact.
The community is determined by the users, not the platform. Each instance has its own culture, its own conventions, its own demographic. Users select into instances that match their interests, and the federation lets them interact with users on other instances. The result is a much more diverse landscape than the platforms provide, with instances ranging from large general-purpose servers to small special-interest communities to single-user personal instances. The federation lets all of these coexist and interact while preserving their distinct identities.
The algorithmic feed is not, by default, present. Most ActivityPub-based services display content chronologically, without the engagement-optimized ranking that the platforms have moved toward. Users see what their followed accounts post in the order they post it, without the platform deciding what to surface and what to bury. This is a structural property of the protocol design, not an accident, and it produces a user experience that many users find more sustainable than the platforms’ algorithmic feeds.
What the fediverse gets wrong
The fediverse also has real problems, which it would be dishonest not to name.
Search is difficult. ActivityPub does not have native federated search, and the various search implementations that exist are limited. Finding people and content across the federation is much harder than on the platforms. Mastodon’s recent addition of optional full-text search has helped within individual instances, but cross-instance search remains underdeveloped. The discovery problem — how a new user finds people to follow — has been a persistent friction point for fediverse growth.
The user experience is, in many respects, rougher than the platforms. The fediverse clients are produced by various small teams with limited resources; the polish that the platforms have through their multi-hundred-person product organizations is not, in most fediverse clients, present. Onboarding is hard: a new user has to choose an instance, and the choice is consequential, and the user has no good way to evaluate the choice before making it. The various features that platform users take for granted (group messaging, video calls, integrated commerce, scheduling) are absent or rudimentary.
The federation has its own pathologies. Instance defederation — the decision by one instance’s operators to stop accepting messages from another instance — is sometimes used appropriately to handle abusive instances, and is sometimes used in ways that produce communities effectively cut off from the larger federation. The dynamics of who gets defederated by whom and why have, particularly in the post-2022 period, produced significant tension within the fediverse community. The federation that works is the federation in which operators cooperate; when cooperation fails, the federation fragments.
The economic model is unclear. ActivityPub-based services do not, generally, have advertising. Most are run by their operators as volunteer or paid-by-the-community efforts; some are funded by their developers’ personal resources; some are running on grants. The sustainability of this economic structure at scale is an open question. Mastodon the project itself has nonprofit foundation status with several full-time staff; the various other fediverse projects have varied funding situations, and many are dependent on the continued willingness of small teams to maintain them for limited compensation.
The IndieWeb
The IndieWeb is a smaller and older movement than the fediverse, with a different theory of change. The principal founders are Tantek Çelik, Aaron Parecki, Kevin Marks, and others who began articulating the IndieWeb position around 2010. The movement’s central premise is that individuals should publish on their own websites, on their own domains, with their own hosting, and that the social-network functions (following, replying, liking, sharing) should be implemented through interoperable protocols across these personal sites. The IndieWeb is, in a sense, the original web’s federation recovered through deliberate practice: people writing on their own pages, linking to each other, and using protocols that make the cross-referencing visible.
The IndieWeb’s principal protocols are:
Microformats, especially h-entry, h-card, and h-feed. These are conventions for marking up HTML pages with structured social-network data — posts, profiles, feeds — that other tools can parse. A web page that includes h-entry markup can be consumed by IndieWeb-aware tools as a post in a federated network. The microformats approach has the property of being readable both by humans (as ordinary HTML pages) and by machines (as structured data), without requiring separate JSON or RSS feeds. The original microformats specifications go back to 2004 and have continued to be developed.
Webmention, a W3C Recommendation since January 2017. Webmention specifies how a citing page can notify a cited page of the citation. The mechanism is simple: when page A links to page B, page A sends a POST request to page B’s webmention endpoint with the URLs of both pages; page B verifies the link, stores the mention, and may display it on page B as an incoming reference. The result is that two-way linking, which the original web rejected for permissionlessness, is recovered for sites that opt in to the protocol.
Micropub, a W3C Recommendation since May 2017. Micropub specifies a standard API for publishing posts to one’s own website from third-party clients. The pattern decouples the publishing client from the publishing destination: a Micropub-aware editor can publish to any Micropub-compliant site, and a Micropub-compliant site can be published to by any Micropub-aware client. This is, in effect, the federated publishing protocol the platforms have replaced with their own proprietary APIs.
IndieAuth, an ongoing standardization effort, provides a domain-based identity protocol. The user’s identity is their domain (you are example.com); authentication to other sites uses OAuth-style flows with the user’s own domain as the identity provider. The result is that the user’s domain becomes a portable identity that the user controls, in contrast to the platform-issued identities that depend on the platform’s continued existence.
POSSE — Publish on Own Site, Syndicate Elsewhere — is the IndieWeb’s recommended publishing pattern. The canonical version of a piece of content lives on the user’s own site; copies are syndicated to platforms (Twitter, Facebook, Mastodon, wherever the user has accounts) for the purpose of reaching audiences that are on those platforms. The pattern means that, if any of the platforms goes away or kicks the user off, the canonical content remains on the user’s own site, with its own URL and its own persistence.
The IndieWeb has held annual IndieWebCamps since 2011 and a regular schedule of online and in-person events. The community is small — perhaps in the low thousands of active participants globally — but it has been steady, productive, and persistent. The community’s output includes the various W3C Recommendations listed above, a substantial corpus of tooling (the IndieWeb’s “Building Blocks”), a wiki of best practices, and a sustained intellectual contribution to thinking about what personal web publishing can be.
Why the IndieWeb has been small but influential
The IndieWeb’s user base is, taken at face value, tiny compared to either the fediverse or the platforms. The movement is, however, influential well beyond its user base for several reasons.
The IndieWeb has been intellectually productive. The community has produced careful, well-articulated specifications and best practices. The Microformats and IndieWeb wikis are substantial repositories of design thinking about personal publishing. The work has been peer-reviewed in the W3C and IETF, has produced standards, and has been adopted (in various subsets) by adjacent projects.
The IndieWeb has been technically generative. The various IndieWeb building blocks have been adopted by other projects, often without direct credit. Webmentions have been added to comment systems beyond the IndieWeb (most prominently to the Jekyll-based static-site generator ecosystem). Micropub has been implemented by clients that publish to fediverse servers. The IndieWeb’s thinking has influenced people who do not consider themselves part of the movement.
The IndieWeb has been culturally consequential. The argument that “you should have your own website” has, since around 2018, been adopted by various people and communities who were not previously part of the IndieWeb. The static-site renaissance (chapter twenty-three) is partly downstream of this cultural shift; the renewed interest in personal blogging through the 2020s has been informed by IndieWeb thinking even where the specific IndieWeb technologies are not used.
The IndieWeb’s small size is, in part, a function of its high cost of entry. The pattern requires the user to set up their own website, write or configure their own publishing tools, and maintain the infrastructure. This is, by the standards of the platform-decade consumer internet, a substantial commitment. The IndieWeb’s response has been to lower the floor gradually — through tools like Micro.blog (a hosted IndieWeb-aware publishing service), through specific IndieWeb-aware static-site templates, and through documentation aimed at less-technical users — but the floor remains high enough that mass adoption is unlikely without further development.
The alternative protocols
The two principal alternative protocols to ActivityPub that have emerged in recent years are AT Protocol and Nostr.
AT Protocol (Authenticated Transfer Protocol) is the substrate behind Bluesky, the social-network application that was announced by Jack Dorsey at Twitter in 2019, spun off as a separate organization in 2022, and launched publicly in 2023 after a period of invitation-only beta. AT Protocol differs from ActivityPub in several important respects. Identities are based on decentralized identifiers (DIDs) that are portable across servers, with cryptographic signatures providing identity continuity. Content is stored in repositories that are, in principle, replicable across servers. The network has explicit support for portable accounts: a user can move their account from one server to another without losing their data, their followers, or their history. The protocol was designed with the lessons of the early fediverse in mind and addresses several of ActivityPub’s known limitations.
AT Protocol’s adoption has been substantial but limited compared to the fediverse. Bluesky itself has grown rapidly since its 2023 public launch, with millions of users by 2024 and continued growth into 2026. The protocol is open and other implementations exist, but Bluesky the application remains the dominant deployment. Whether AT Protocol becomes a genuinely federated network in the way ActivityPub is — with many independent servers running different applications and interoperating — or becomes a single-vendor protocol that Bluesky the company controls is, in 2026, still being decided. The protocol’s technical merits are real; the federation properties depend on the social and economic structures around the protocol developing in a federation-friendly direction.
Nostr (Notes and Other Stuff Transmitted by Relays) is a simpler and more radical alternative protocol, designed by the developer known as fiatjaf in 2020. Nostr’s core model is that clients publish signed messages to relays, and relays propagate messages between clients. There is no concept of an account; users are identified by public keys. Relays are dumb message-forwarders; the application logic lives in clients. The protocol is much simpler than ActivityPub and supports a different model of federation, in which the user controls their identity (the keypair), the relays are interchangeable, and clients can read from and write to any combination of relays.
Nostr has acquired a substantial user base, particularly among Bitcoin-aligned communities, and has produced a working ecosystem of clients, relays, and applications. The protocol’s strengths are its simplicity and the strong identity properties of keypair-based addressing. The protocol’s weaknesses include the user-experience challenges of key management at scale, the spam-and-abuse handling that the dumb-relay model makes harder, and the discovery problem that’s even worse than ActivityPub’s. Nostr is, in 2026, a smaller but technically interesting alternative whose long-term trajectory is uncertain.
What has been recovered
A summary of what the federation recovery has achieved in 2026:
A genuinely federated social network. The fediverse, with several million users across tens of thousands of servers, is the largest federated social network since Usenet. The recovery is real and is operating at non-trivial scale.
Multiple coexisting protocols and implementations. ActivityPub, AT Protocol, and Nostr are different proposals for how federated social networks should work, each with working implementations and user bases. The diversity is itself a recovery: the platform decade had reduced the social-network space to a few centralized options, and the recovery has produced multiple alternatives.
Standards and tooling for federated publishing. The W3C Recommendations (ActivityPub, ActivityStreams, Webmention, Micropub) and the various surrounding tools and libraries constitute a substantial body of infrastructure that did not exist a decade ago. Building federated applications is now significantly easier than it was.
A user community that takes federation seriously. The fediverse and IndieWeb communities have built up, over the past five-to-ten years, a substantial corpus of practice and culture around federated social networking. The community’s existence is itself a recovery of the kind of culture that supported pre-platform online communities.
What has not yet been recovered
The platforms’ user bases. Facebook, Instagram, WhatsApp, and similar services each have several hundred million to several billion users. The federated alternatives have, collectively, perhaps ten million. The recovery has not achieved scale comparable to the consolidation it is responding to.
The platforms’ product polish. The federated alternatives are improving but still lag the platforms in many user-experience dimensions. Onboarding, search, content discovery, mobile apps, integrated features — the platforms have invested billions in these areas and the federated alternatives have invested millions.
A working answer to economic sustainability. The platforms are funded by advertising and the various business models that the federated alternatives have tried have not yet shown they can support comparable infrastructure at comparable scale.
A complete replacement for the platforms’ role in public discourse. Significant fractions of public discussion still happen on the platforms, and the federated alternatives have not yet displaced the platforms as the venue for broad-audience discussion. The 2022-2023 surge to Mastodon was an indication of what could happen if the platforms collapsed faster than they have, but the platforms have not collapsed and the federation has not, so far, been positioned to absorb the role.
The trajectory
The federation recovery is, in 2026, on an upward trajectory but a slow one. The fediverse is larger than it was five years ago and is likely to be larger still in five more years. The IndieWeb is more visible than it was. The alternative protocols are producing serious working systems. The cumulative effect, summed across the various recoveries, is that the federation alternative is more credible in 2026 than it has been at any point since the platform consolidation began.
The recovery has, however, several preconditions for further growth that are outside the control of the recovery’s participants. The platforms have to continue producing the kind of dissatisfaction that drives users to alternatives. Regulatory pressure on the platforms has to continue. The cost of running federated infrastructure has to remain accessible to community-funded operators. The technical maturation of the federated tools has to continue at a pace that closes the gap with the platforms’ polish. None of these are guaranteed.
The recovery is, then, real but partial. It is the most visible of the recoveries in Part V because it has user numbers that approach the level of significance, but it is not yet a comprehensive answer to the platform consolidation. The federation experiment continues. The next chapter takes a different recovery, oriented around documents rather than social networks: the static renaissance, the return to Markdown and static site generators and the Gemini protocol, as a deliberate retreat from the application web back toward something the web’s original document architecture had supported and that has been gradually rediscovered as still useful.