Fediverse is a portmanteau of "federation" and "universe". It is a common, informal name for a somewhat broad federation of social network servers whose main purpose is microblogging, the sharing of short, public messages. By running social network software that supports a standard set of protocols called ActivityPub, independently run servers can connect to the Fediverse,[1] allowing its users to follow and receive short messages from each other, regardless of which particular ActivityPub server implementation they are running. https://en.wikipedia.org/wiki/Fediverse See esp Mastodon. See related IndieWeb.

Some would say this should include non-ActivityPub services which have a federation model: BlueSky and Threads. Recall that Mastodon doesn't support all of ActivityPub.

• Aug'2024: Boris Mann thread on MAU stats
  • Do people want me to point out that Bluesky has more monthly active users than all ActivityPub instances?
  • Misskey is probably above 100K MAUs

Dec'2022: Where might this go?

Claims/Forces

• For comparison, Twitter usage is currently 217M DAU (est 495M MAU). Mastodon usage is ~2.5M MAU (per (2022-12-08) Mastodon Growth Numbers Might Not Mean What You Think They Mean Absolutely Maybe).
• Mastodon isn't the only system in the Fediverse: (2022-11-02) Axbom The Many Branches Of The Fediverse
• every flavor of the Fediverse will involve multiple servers (with varying features) and multiple client apps (with varying features), and multiple add-on tools/servers like info sites, onboarding guides, search engines, etc
  • this creates multiple possible "targets" for a group of dissatisfied users are with common needs
• There will probably be a roughly PowerLaw curve of app size, server size, and client-app (adoption) size.
• Despite open protocols, Apple (iPhone iCloud) and gmail dominate email-hosting.
• Some servers will be run as commercial enterprises.
• Some commercial servers will aim to be just-sustainable Indie biz (cf MetaFilter - 6k MAU?)
• Some servers will hope to become a BigCo.
• Some servers will be run as hobbies, like old BBS systems. They may have some way to at least cover their hard-expenses, but will probably generate no significant income for the operator.
  • InfoWorld estimated that there were 60,000 BBSes serving 17 million users in the United States alone in 1994.
• Some servers will be explicitly/legally structured as CoOps.
• Many non-big servers will churn, like indie restaurants.
• Hobby/indie servers will probably max out at ~1k DAU (2.5k MAU) (source?) based on moderation hassles. You'd need 200k such servers to match Twitter usage.
• Will Big servers default-opt-in federating Small servers? Will Small servers default-opt-in federating Small servers?

Solutions

• if you care, export your archive and post it on your own server: PESOS.