Best Self-hosted Calendars & Contacts (CalDAV/CardDAV) tools in 2026
27 self-hosted open source alternatives in this category
See also:
Collaborative Office SuitesEmail Servers (SMTP/IMAP)Team Chat & MessagingVideo Conferencing & WebRTCVoIP / SIP & PBXWebmail Clients27 services found
Nextcloud
Open-source collaboration platform for file sync and groupware
Nextcloud is an open-source content collaboration platform providing file sync & share, groupware (calendar, contacts, mail), real-time office editing, chat and video con...
Stalwart Mail Server
All-in-one mail and collaboration server for modern and legacy protocols
All-in-one open-source mail and collaboration server with SMTP, IMAP, JMAP, CalDAV, CardDAV, and WebDAV, plus integrated anti-spam and phishing protection.
ownCloud
Open-source file sync, share and collaboration platform
Open-source platform for secure file sync, sharing, collaboration, calendars and external storage with WebDAV/CalDAV/CardDAV support.
Radicale
CalDAV and CardDAV server for calendars, tasks, and contacts
Lightweight CalDAV/CardDAV server for syncing calendars, to-dos, and contacts with many clients, storing data on the filesystem and supporting auth and TLS.
Baïkal
Lightweight CalDAV and CardDAV server for calendars and contacts
Baïkal is a lightweight CalDAV/CardDAV server with a web admin UI for managing users, calendars, and address books, backed by MySQL or SQLite.
NextcloudPi
Preconfigured Nextcloud image and management panel for SBCs
Prebuilt Nextcloud appliance and management tools for Raspberry Pi, Odroid, VMs and LXC; includes Apache, PHP, MariaDB, Redis, web panel and backup utilities.
SOGo
Scalable groupware server with webmail, calendars, and contacts
Open source groupware suite providing webmail, calendaring, address books, and shared resources via open standards like IMAP, CalDAV, and CardDAV.
iRedMail
Open-source full-featured mail server stack for Linux/BSD
Automated open-source mail server installer bundling Postfix, Dovecot, webmail, anti-spam/antivirus and LDAP/SQL backends for mainstream Linux/BSD.
EteSync
End-to-end encrypted sync for calendars, contacts, tasks and notes
EteSync (Etebase Server) provides a self-hostable, zero-knowledge, end-to-end encrypted sync backend for calendars, contacts, tasks and notes across devices.
sabre/dav
PHP framework for WebDAV, CalDAV, and CardDAV servers
sabre/dav is a PHP framework for building WebDAV file servers and CalDAV/CardDAV calendar and contacts services.
FluidCalendar
Intelligent task scheduling and calendar management app
Open-source task scheduler and calendar app that auto-plans tasks, syncs with external calendars, and provides a modern UI for managing time blocks and workflows.
DavMail
Exchange and Microsoft 365 gateway for standard mail and PIM protocols
DavMail is a Java gateway that lets standard clients use IMAP/POP/SMTP, CalDAV, CardDAV, and LDAP with Microsoft Exchange and Microsoft 365 via OWA/EWS.
Davis
CalDAV/CardDAV/WebDAV server with a Symfony-based admin interface
Davis is a sabre/dav-based CalDAV/CardDAV/WebDAV server with a modern Symfony 7 admin dashboard for managing users, calendars, sharing, and address books.
Nextcloud Tasks
Task management app for Nextcloud with CalDAV sync
Nextcloud Tasks provides a web-based to-do list with priorities, due dates, subtasks, and CalDAV synchronization with mobile and desktop task clients.
Cyrus IMAP
Email, contacts, and calendar server with IMAP and JMAP
Cyrus IMAP is a secure, scalable mail server providing IMAP/JMAP email plus CalDAV/CardDAV contacts and calendars, with ACLs, quotas, search, and replication.
Xandikos
CalDAV/CardDAV server that stores data in a Git repository
Lightweight CalDAV/CardDAV server implemented in Python that stores calendars and contacts in a Git-backed hierarchy with history and sync support.
Manage My Damn Life
Self-hosted web front end for CalDAV calendars and tasks
Self-hosted Next.js React CalDAV client for managing VTODO tasks and VEVENT calendars with multi-account, list/Gantt/calendar views and filters.
Hitobito
Open-source platform for managing memberships, events and organizations
Open-source web application for complex organization hierarchies: members, events, courses, mailings and payments. Plugin-based, Rails-backed, community-driven.
EGroupware
Open-source web-based groupware for calendars, mail, files and projects
Open-source, browser-based groupware providing calendar, email, file manager, CRM, projects, Collabora Online integration and SSO support.
Spacepad
Privacy-focused room display and booking system for workplaces
Self-hostable room display app for tablets that shows real-time room availability, integrates with Microsoft 365, Google Workspace and CalDAV, and supports on-device book...
Group-Office
Enterprise groupware and CRM with calendars, files and email
PHP-based groupware and CRM for teams: calendars, contacts, email, file management, projects and CRM with CalDAV/CardDAV/IMAP support and extensible modules.
Meetable
Minimal Laravel-based events aggregator and listing platform
Open-source event listing and aggregator built on Laravel. Provides iCal feeds, tags, RSVP, photos, and multiple authentication methods for community and organization eve...
tine
PHP-based modular groupware for calendar, contacts, email, CRM and files
Open-source PHP groupware providing CalDAV/CardDAV, ActiveSync, email client, CRM, tasks, file manager and Docker images for on-premise collaboration.
Zimbra Collaboration
Enterprise email, calendar, contacts, and collaboration suite
Self-hosted enterprise collaboration suite providing email, webmail, calendaring, contacts, and administration for organizations.
Citadel
Groupware server with email, calendaring, contacts, and web access
Citadel is an open source groupware and messaging server providing email, calendars, contacts, and a web interface with room-based collaboration.
HiveDAV
Curlable free/busy scheduler with CalDAV integration
A lightweight, curl-first free/busy scheduler that syncs availability from a CalDAV calendar and can send iCal booking invites via SMTP.
DAViCal
CalDAV server for shared calendars and scheduling
DAViCal is an open source CalDAV/WebDAV calendar server using PostgreSQL, enabling shared calendars, access delegation, and meeting scheduling across many clients.