This is a list of federated social clients and other related tools that use protocols other than those used in the fediverse (OStatus, ActivityPub, Diaspora, DFRN, Zot)
The blockchain social apps list has its own page, because although all these apps are distributed in some way (because they use a blockchain), they're not all federated with anything other than other copies of their own app.
DAT is a distributed (non-blockchain) ledger & peer-to-peer data sharing toolkit, that can work offline or with poor connectivity, and uses the Hypercore protocol under the hoods. The DAT ecosystem is community developed under guidance of the non-profit Dat Foundation.
DAT Projects lists a number of interesting projects that are under the Dat Foundation umbrella.
Pushpin is a collaborative digital workspace that works offline and syncs in real-time.
Matrix is a federated web protocol, used mainly so far for realtime chat rooms.
Secure Scuttlebutt (SSB) is a decentralized social network, running on a peer-to-peer secure gossip platform. It is based on the Scuttlebutt Protocol for building decentralized applications that work well offline and that no one person can control.
Patchwork (supporting Linux, MacOS, and Windows) is a stand-alone SSB client that provides a beginner-friendly social view of Scuttlebutt.
Patchbay (supporting Linux, MacOS, and Windows) is an SSB client that provides a bleeding-edge, tab-based interface with experimental features.
Manyverse (supporting Android, iOS) is an SSB mobile client, currently in beta.
Patchfox packaged as a Web Extension for Firefox provides a new way to access Scuttlebutt. It requires running either sbot, Patchwork or Patchbay.
Movim is a web client with social network features, written in PHP and uses
eJabberd (Erlang) backendany XMPP server with XEP-0060 PubSub support. Users can login to any Movim instance using any XMPP account, just as they can login to any Pinafore instance using any Mastodon account.
Salut à Toi (includes the Libervia web client) is a social network based on XMPP/Jabber.