Radicale
Simple calendar and contact server with extremely low administrative overhead.
Self-hosted Calendar & Contacts software
CalDAV and CardDAV protocol servers and web clients/interfaces for Electronic calendar, address book and contact management.
10 apps, ranked by GitHub stars weighted by maintenance health.
Baïkal
Lightweight CalDAV and CardDAV server based on sabre/dav.
SabreDAV
CardDAV, CalDAV, and WebDAV framework and server.
Keeper.sh
Calendar syncing tool that pulls and pushes events between calendar sources and destinations via iCal/ICS or OAuth, with support for anonymized busy/free events.
DavMail
POP/IMAP/SMTP/Caldav/Carddav/LDAP exchange gateway allowing users to use any mail/calendar client with an Exchange server, even from the internet or behind a firewall through Outlook Web Access.
Davis
Simple, dockerizable and fully translatable admin interface for sabre/dav based on Symfony 5 and Bootstrap 4, largely inspired by Baïkal.
Manage My Damn Life
Manage my Damn Life (MMDL) is a front end for managing your CalDAV tasks and calendars.
Xandikos
CardDAV and CalDAV server with minimal administrative overhead, backed by a Git repository.
dayGLANCE
Day planner with drag-and-drop time blocking, inbox, recurring tasks, habits, routines, goals, projects and Pomodoro focus mode, plus iCal and CalDAV calendar sync. Data stays in the browser, with optional WebDAV or GLANCEvault sync.
DAViCal
Server for calendar sharing (CalDAV) that uses a PostgreSQL database as a data store.