The Fediverse (a portmanteau of "federation" and "universe") is an ensemble of federated (i.e. interconnected) servers that are used for web publishing (i.e. social networking, microblogging, blogging, or websites) and file hosting, but which, while independently hosted, can communicate with each other. On different servers (instances), users can create so-called identities. These identities are able to communicate over the boundaries of the instances because the software running on the servers supports one or more communication protocols which follow an open standard. As an identity on the fediverse, users are able to post text and other media, or to follow posts by other identities. In some cases, users can even show or share data (video, audio, text, and other files) publicly or to a selected group of identities and allow other identities to edit other users' data (such as a calendar or an address book).
In 2008, the social network identi.ca was founded by Evan Prodromou. He published the software GNU social under a free license (GNU Affero General Public License, AGPL). It defined the OStatus protocol. Besides the server, identi.ca, there were only few other instances, run by persons for their own use. This changed in 2011–12 when identi.ca switched to another software called pump.io. Several new GNU social instances were created. At the same time as GNU social, other projects like Friendica, Hubzilla, Mastodon, and Pleroma integrated the OStatus protocol, thus extending the fediverse. In the meantime, other communication protocols evolved which were integrated to different degrees into the platforms
In January 2018, the W3C presented the ActivityPub protocol, aiming to improve the interoperability between the platforms. As of August 2018[update], this protocol was supported by thirteen platforms (see table below), and was the dominant protocol used in the fediverse.
Communication protocols used in the fediverse
Fediverse software platforms
The software spanning the fediverse are clarification needed] FOSS. Some of them vaguely resemble Twitter in style (for example, Mastodon, Misskey, GNU social, and Pleroma, which are similar in their microblogging function), while others include more communication and transaction options that are instead comparable to Google+ or Facebook (such as is the case with Friendica and Hubzilla).[
The following software platforms span the fediverse by using the listed communication protocols:
|Anfora||Image hosting||In progress ||No||No||No|
|diaspora* software||Social network, Microblogging||No||Yes||No||No|
(f. Friendika; orig. Mistpark)
|Social network, Microblogging||Yes||Yes||Yes||No|
|Funkwhale||Audio, sound hosting||Yes||No||No||No|
|GNU MediaGoblin||file, image, audio, video hosting||Proposed ||No||No||No|
(f. StatusNet; orig. Laconica)
|Microblogging||Proposed  ||No||Yes||No|
(f. RedMatrix; orig. Friendica-Red)
|CMS, Social network, Microblogging, Wiki, Blogging, Image gallery, File hosting||Yes||Yes||Yes ||Yes|
|Kibou||Social network, Microblogging||Yes||No||No||No|
|Lemmy||Link Aggregator, Social Network (Based on Reddit)||In Progress||No||No||No|
|Littr.me||Link Aggregator, Social Network||In progress||No||No||No|
|Mastodon||Microblogging||Yes ||No||Dropped ||No|
|Misskey||Social network, Microblogging||Yes||No||No||No|
|Nextcloud Social||File hosting||Yes ||No||No||No|
|Nodetube||Video hosting||In Progress||No||No||No|
|Pubcast (f. Metapods)||Netcasting||Yes||No||No||No|
|pump.io||Microblogging||Proposed ||No||Dropped ||No|
|Read.as||Feed reader||Yes ||No||No||No|
|Socialhome||Website, Social network, Microblogging||Yes||Yes||No||Proposed|
|Write.as / WriteFreely||Blogging||Yes||No||No||No|
|Zap||Social network, Macroblogging, Image gallery, File hosting||Yes||No||No||Zot/6|
A number of developers publish live statistics about the fediverse on monitoring sites  like fediverse.network and the-federation.info. The statistics on these sites are an indication of usage levels, not a complete record, as they can only aggregate data from instances that use the NodeInfo protocol to publish usage statistics. There is no guarantee that all instances are known to these sites, and some instances may disable NodeInfo, or use software that hasn't implemented it. Some of these sites include data from any federated software that publishes it using NodeInfo, not just fediverse software.
- "Fed FAQ". Mastodon User Guide. Archived from the original on 2017-04-09.
- "What on Earth is the fediverse and why does it matter?". New Atlas.
- "gnusoc · master / addons". Hubzilla. Framagit. Retrieved 2018-07-17.
- "Pleroma". Retrieved 2018-07-17.
- Macgirvin, Michael ‘Mike’. "Zot/6". Retrieved 2018-09-14.
- "Zot Protocol". Hubzilla. Archived from the original on 2018-08-18. Retrieved 2018-08-18.
- "Misskey". Retrieved 2019-05-02.
- "Implement mastodon API endpoints #23". Anfora. Git hub. Retrieved 2018-12-10.
- diaspora*. "Support ActivityPub #7422". Retrieved 2018-08-18.
- diaspora*. "Let's talk about ActivityPub". Retrieved 2018-08-18.
- funkwhale. "Funkwhale". Retrieved 2019-05-02.
- GNU MediaGoblin. "Move federation code to ActivityPub spec #5503". Archived from the original on 2017-04-11. Retrieved 2018-08-18.
- GNU social. "Support ActivityPub #256". Retrieved 2018-08-18.
- GNU social. "Plugin". Retrieved 2018-08-18.
- Mastodon. "ActivityPub support #1557". Retrieved 2018-08-18.
- Mastodon. "Release v3.0.0". Retrieved 2019-10-08.
- Nextcloud. "Nextcloud introduces social features, joins the fediverse". Retrieved 2018-12-10.
- mayeaux (2020-02-09), mayeaux/nodetube, retrieved 2020-02-11
- Pixelfed. "Pixelfed". Retrieved 2019-05-02.
- Pixelfed. "Pixelfed federates now". Retrieved 2018-12-31.
- Pleroma. "ostatus removal". Retrieved 2019-12-29.
- joinplu.me. "Plume". Retrieved 2019-05-02.
- pump.io. "ActivityPub support #1241". Retrieved 2018-08-18.
- pump.io. "OStatus #8". Retrieved 2018-08-18.
- Read.as. "Long-form ActivityPub-enabled reader". Retrieved 2018-08-29.
- Robinson, Jason (May 19, 2018). "Implementing Zot".
- 2019. The disinformation landscape and the lockdown of social platforms
- 2019. Challenges in the Decentralised Web: The Mastodon Case
- 2018. Recommending Users: Whom to Follow on Federated Social Networks
- 2018. Multi-task dialog act and sentiment recognition on Mastodon
- 2015. FCJ-190 Building a Better Twitter: A Study of the Twitter Alternatives GNU social, Quitter, rstat.us, and Twister
- 2015. The Case for Alternative Social Media