Distributed social network
A distributed social network or federated social network is an Internet social networking service that is decentralized and distributed across distinct providers (something like email but for social networks). It consists of multiple social websites, where users of each site communicate with users of any of the involved sites. From a societal perspective, one may compare this concept to that of social media being a public utility.
A social website participating in a distributed social network is interoperable with the other sites and is in federation with them. Communication among the social websites is technically conducted over social networking protocols. Software used for distributed social networking is generally portable so it is easily adopted on various website platforms. Distributed social networks contrast with social network aggregation services, which are used to manage accounts and activities across multiple discrete social networks.
A few social networking service providers have used the term more broadly to describe provider-specific services that are distributable across different websites, typically through added widgets or plug-ins. Through the add-ons, the social network functionality is implemented on users' websites.
Comparison of software and protocols 
Open standards such as OAuth authorization, OpenID authentication, OStatus federation, ActivityPub federation protocol, XRD metadata discovery, the Portable Contacts protocol, the Wave Federation Protocol, the Extensible Messaging and Presence Protocol (XMPP) (aka Jabber), OpenSocial widget APIs, microformats like XFN and hCard, and Atom web feeds—increasingly referred to together as the Open Stack—are often cited as enabling technologies for distributed social networking.
The Electronic Frontier Foundation (EFF), a U.S. legal defense organization and advocacy group for civil liberties on the Internet, endorses the distributed social network model as one "that can plausibly return control and choice to the hands of the Internet user" and allow persons living under restrictive regimes to "conduct activism on social networking sites while also having a choice of services and providers that may be better equipped to protect their security and anonymity".
The World Wide Web Consortium (W3C), the main international standards organization for the World Wide Web, launched a new Social Activity in July 2014 to develop standards for social web application interoperability.
- Data portability
- Collective intelligence
- Diaspora (social network)
- Geosocial networking
- GNU social
- Mastodon (software)
- Mobile social network
- Personal network
- Professional network service
- Social identity
- Virtual community
- Sonic project
- Recordon, David (2008-10-09). ""Blowing Up" Social Networks by Going Open". p. 27. Retrieved 5 January 2009.
- Richard Esguerra (March 21, 2012). "An Introduction to the Federated Social Network". Electronic Frontier Foundation Deeplinks Blog.
- "W3C Launches Push for Social Web Application Interoperability". World Wide Web Consortium. 21 July 2014.
- Diploma Thesis from the University of Applied Sciences Dresden(HTW) about XMPP-based Federated Social Networks like buddycloud[dead link](CC-BY)
- Paper on FOAF in an Android environment by Tramp, S., Frischmuth, P., Arndt, N., Ermilov, T., and Auer, S. (2011). Weaving a distributed, semantic social network for mobile users. In Antoniou, G., editor, ESWC 2011, Part I, LNCS 6643, pages 200–214.