Radicale : The Radicale Project is a complete CalDAV (calendar) and CardDAV (contact) server solution.
Postal : Postal is a complete and fully featured mail server for use by websites & web servers. Think Sendgrid, Mailgun or Postmark but open source and ready f...
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...
Gitea is a community managed fork of Gogs, lightweight code hosting solution written in Go and published under the MIT license.