Radicale : The Radicale Project is a complete CalDAV (calendar) and CardDAV (contact) server solution.
deepstream.io : A Scalable Server for Realtime Web Apps
Stores and syncs data in realtime
Built in node.js
Works for browsers, backend & mobile
Scales via clustering...
RoadRunner : RoadRunner is an open source (MIT licensed), high-performance PSR-7 PHP application server, load balancer and process manager. It supports service mod...
Matrix : Matrix is an open standard for decentralised communication, providing simple HTTP APIs and open source reference implementations for securely distribu...
Growth Book : Growth Book is an open source experimentation platform designed for companies that want to bring A/B testing in-house, but don't want to build it them...
Baïkal offers ubiquitous and synchronized access to your calendars and address books over CalDAV and CardDAV. Baïkal implements the current IETF recommendation drafts of these industry standards for centralized calendar and address book collections.