- [Baïkal](http://sabre.io/baikal/) - Lightweight CalDAV and CardDAV server based on sabre/dav. ([Source Code](https://github.com/sabre-io/Baikal)) `GPL-3.0``PHP`
- [CalendarServer](https://www.calendarserver.org/) - Apple, Inc.'s standards-compliant server implementing the CalDAV and CardDAV protocols shipped with macOS Server. ([Source Code](https://github.com/apple/ccs-calendarserver)) `Apache-2.0``Python`
- [calypso](https://keithp.com/calypso/) - Python-based CalDAV and CardDAV server, forked from Radicale. ([Source Code](https://keithp.com/git/calypso.git)) `GPL-3.0``Python`
- [DAViCal](https://www.davical.org/) - Server for calendar sharing (CalDAV) that uses a PostgreSQL database as a data store. ([Source Code](https://gitlab.com/davical-project/davical)) `GPL-2.0``PHP`
- [Davis](https://github.com/tchapi/davis/) - A simple, dockerizable and fully translatable admin interface for sabre/dav based on Symfony 5 and Bootstrap 4, largely inspired by Baïkal. `MIT``PHP`