DAVx⁵

CalDAV/CardDAV Synchronisation and ClientGPL-3.0-only

Infomaniak kSync

Automatically sync your contacts and calendarsGPL-3.0-only

DecSync CC

Sync contacts, calendars and tasks without a server using DecSyncGPL-3.0-only

Nextcloud

Synchronization clientGPL-2.0-only