CalDAV server implementations

Known CalDAV server implementations.

Open Source

• Baikal — Lightweight CalDAV/CardDAV server in PHP.
• Radicale — Simple CalDAV/CardDAV server in Python.
• Sabre/DAV — CalDAV/CardDAV framework in PHP (used by Nextcloud, Baikal).
• CalendarServer — Apple’s open-source CalDAV server (Python).
• Dovecot — IMAP server with CalDAV extension.
• Kolab — Groupware server with CalDAV support.
• OpenXChange — Groupware platform with CalDAV.

Commercial

• Apple Calendar Server (macOS Server)
• Google Workspace — CalDAV access for Google Calendar.
• Microsoft Exchange — CalDAV via third-party gateways.
• Zimbra — Collaboration server with native CalDAV.