Cal.diy
Calendar & ContactsOnline appointment scheduling system
Replaces Calendly, Doodle
Best Cross-Platform Calendar & Contacts for self-hosting
The 11 best Cross-Platform calendar & contacts you can self-host, ranked by community traction.
vdirsyncer
Calendar & ContactsSynchronize calendars and contacts via CalDAV/CardDAV
Replaces iCloud sync
Alf.io
Calendar & ContactsTicket reservation system
AgenDAV
Calendar & ContactsCalDAV web client with an Ajax interface
Replaces Google Calendar
DavMail
Calendar & ContactsPOP/IMAP/SMTP/Caldav/Carddav/LDAP exchange gateway allowing users
Decsync Calendar Sync
Calendar & ContactsFile-based calendar and contacts synchronization
Replaces Google Calendar
hitobito
Calendar & ContactsManage complex group hierarchies with members, events and a lot more
GNOME Calendar
Calendar & ContactsSimple desktop calendar with CalDAV support
Replaces Google Calendar
Meetable
Calendar & ContactsMinimal events aggregator
KOrganizer
Calendar & ContactsCalendar and scheduling component of KDE Kontact
Replaces Outlook Calendar
Digistorm
Calendar & ContactsCreate collaborative surveys, quizzes, brainstorms, and word clouds
No apps match these filters.
At a glance
| App | Deploy effort | Difficulty | Min. RAM | License | ★ Stars |
|---|---|---|---|---|---|
| Cal.diy | Read-the-docs project | Medium | 512 MB | MIT | 48,984 |
| vdirsyncer | Read-the-docs project | Medium | 64 MB | BSD-3-Clause | 1,888 |
| Alf.io | Read-the-docs project | Medium | 512 MB | GPL-3.0 | 1,616 |
| AgenDAV | Under-an-hour setup | Medium | 128 MB | GPL-3.0 | 831 |
| DavMail | Read-the-docs project | Medium | 512 MB | GPL-2.0 | 766 |
| Decsync Calendar Sync | Read-the-docs project | Medium | 128 MB | GPL-3.0 | 702 |
| hitobito | Read-the-docs project | Medium | 512 MB | AGPL-3.0 | 483 |
| GNOME Calendar | Read-the-docs project | Easy | 256 MB | GPL-3.0 | 300 |
| Meetable | Read-the-docs project | Medium | 512 MB | MIT | 171 |
| KOrganizer | Read-the-docs project | Medium | 512 MB | GPL-2.0 | 100 |
Quick picks
- Most adopted: Cal.diy (48,984 GitHub stars).
- Lightest footprint: vdirsyncer (from 64 MB RAM, against 512 MB for the heaviest here).
- Licensing: 4 of 11 use GPL-3.0; check the rest individually if you plan to modify and redistribute.
Every option here is open-source and self-hostable, tagged Cross-Platform within the calendar & contacts category. Deploy effort is graded from published container recipes, not vendor claims — see the methodology.