Baïkal - Lightweight CalDAV and CardDAV server based on sabre/dav. (Source Code) GPL-3.0PHP
DAViCal - Server for calendar sharing (CalDAV) that uses a PostgreSQL database as a data store. (Source Code) GPL-2.0PHP/deb
Davis - A simple, dockerizable and fully translatable admin interface for sabre/dav based on Symfony 5 and Bootstrap 4, largely inspired by Baïkal. MITPHP
Etebase (EteSync) - End-to-end encrypted and journaled personal information server supporting calendar and contact data, offering its own clients. (Source Code) AGPL-3.0Python/Django
Manage My Damn Life - Manage my Damn Life (MMDL) is a self-hosted front end for managing your CalDAV tasks and calendars. (Source Code) GPL-3.0Nodejs/Docker
Radicale - Simple calendar and contact server with extremely low administrative overhead. (Source Code) GPL-3.0Python/deb
SabreDAV - Open source CardDAV, CalDAV, and WebDAV framework and server. (Source Code) MITPHP
Xandikos - Open source CardDAV and CalDAV server with minimal administrative overhead, backed by a Git repository. GPL-3.0Python/deb