I currently use fruux (which is proprietary) to synchronise my to-do lists and calendars. However, I was wondering if there was a FOSS CalDAV service which I could use for free.
I have already looked into Nextcloud, and I don't believe it is what I'm looking for. I also don't want to use ProtonCalendar or Tutanota Calendar, as they only work with their own respective apps.
In a nutshell, I would like a service that:
Supports CalDAV
Is free (as in free beer)
Supports both calendars and to-do lists
EDIT: I am able to self-host some apps using Render, but they must be compatible.
I use decsyncCC - which can use a folder as a form of DAV - combined with syncthing across devices. This requires no server and works well, the only problem is idk of any good decsyncCC folder-structure parsers that can be accessed as a local DAV service from the desktop.
Oh ok you should probably clarify that in the OP since everyone is giving you recommendations of self hosted software. It's usually assumed that's what someone's after when they are asking for a FOSS service.