*The fediverse* is a set of federated servers, typically using a communication protocol called [ActivityPub](https://www.w3.org/TR/activitypub) which was devised by the [social working group](https://www.w3.org/wiki/Socialwg) within the World Wide Web Consortium (W3C). At present it is mostly used for [microblogging](https://en.wikipedia.org/wiki/Microblogging), although ActivityPub is sufficiently general that it can also be used for a variety of other purposes.
The word *fediverse* (federated universe) appears to have originated around 2012 as the first [identi.ca](https://en.wikipedia.org/wiki/Identi.ca) website was ending and the [pump.io](https://en.wikipedia.org/wiki/Pump.io) project was beginning. The ActivityPub protocol was initially called *ActivityPump*, due to the influence which pump.io had upon its creation. Fediverse servers are typically referred to as "instances".
Servers such as [Mastodon](https://github.com/mastodon/mastodon) are well known, but these are aimed at large scale deployments on powerful hardware running within data centers, making use of content distribution networks (CDN) and due to their large number of dependencies requiring someone with a high level of systems administration skill to maintain. Epicyon is designed for the opposite situation where it is only intended to have a single user or a small number of users (less than ten) running from your home location or on a modest VPS and where maintenance is extremely trivial such that it's possible to keep an instance running for long durations with minimal intervention.
Epicyon is part of the "small web" category of internet software, in that it is intended to scale via federation rather than to scale vertically via resource intensive and expensive hardware. Think many small communicating nodes rather than a small number of large servers. Also, in spite of the prevailing great obsession with scale, not everything needs to. You can federate with a small number of servers for a particular purpose - such as running a club or hackspace - and that's ok.
It is hardly possible to visit many sites on the web without your browser loading and running a large amount of javascript. Epicyon takes a minimalist approach where its web interface only uses HTML and CSS. You can disable javascript, or use a browser which doesn't have javascript capability, and the user experience is unchanged. Lack of javascript also rules out a large area of potential attack surface.
Epicyon also includes some lightweight organizing features, such as calendar, events and sharing economy features.
