Gitea : Gitea is a community managed fork of Gogs, lightweight code hosting solution written in Go and published under the MIT license.
Riot : Riot allows teams to communicate across a wide range of collaboration apps. If some team members use Riot while others use IRC, Slack or Gitter, Riot ...
Radicale : The Radicale Project is a complete CalDAV (calendar) and CardDAV (contact) server solution.
pump.io : Social server with an ActivityStreams API. It's a stream server that does most of what people really want from a social network.
Sourcegraph : Sourcegraph Server is a free, self-hosted code search server that integrates with your code host and supports multi-repository, regexp, and diff searc...