Compare software

Nextcloud CalendarZimbra
Free

Free app for Nextcloud servers.

 Paid

Sold in several editions under Zimbra's license terms; see the edition comparison.

Web, Self-hosted Web, Self-hosted
  • Calendars stay on your own server
  • CalDAV sync with standard clients
  • Mail, calendar and contacts in one web client
  • Can be run on your own servers
  • Requires a running Nextcloud server
  • Not a standalone app
  • Aimed at organisations rather than individuals
  • Running a mail server takes administration effort
Self-hosted Self-hosted, Hosted service
Open source Closed source
License not stated License not stated
Account needed Not stated if an account is needed
Not stated if it works offline Not stated if it works offline

Checked October 2, 2026

Checked October 1, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.