Open Streaming Platform : Open Streaming Platform (OSP) is an open-source, RTMP streamer software front-end for Arut's Nginx-RTMP Module. OSP was designed as a self-hosted alte...
SimpleLogin : With email aliases , you can be anonymous online and protect your inbox against spams and phishing. Open-source.
Appwrite : Appwrite is an end-to-end backend server for Web, Mobile, Native, or Backend apps packaged as a set of Docker microservices. Appwrite abstracts the co...
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 ...
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.
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 for you to run on your own servers.