@txt_file Oh my, I just switched to Nextcloud a year ago, and it’s soo convenient…
Before, I used SeaFile (file storage) and Baïkal* (CalDAV, CardDAV).
Baïkal doesn’t have a real web GUI, I had infcloud (last update in 2015) and tried AgenDAV (also dead). https://github.com/agendav/agendav