By default there isn’t a single truth. It’s all distributed federated / mesh networked. Any group of machines sharing the same folder, compare metadata about the folder time/date stamps revision history etc, to determine who has the newest folder contents. You can also enable formal version control in the syncthing client on folders if your worried about errors but by default ive seen very few to zero.
I usually run it on my phone, home server and on my laptop. If phone leaves and I change a file, like add an entry to my encrypted password database, phone will update everything else when it comes back into contact with the mesh network again.
Jirafeau is centralized. I run it on lighttpd on a VPS. I mainly use it to share files with people across the web, when sharing a syncthing folder would not be appropriate. You can generate unique links to files with it. It’s basically very similar to Nextcloud’s file sharing, if it was broken out as a stand alone seperate app without a database. Dead simple.
Yeah I run FreeBSD on my VPS. Ubuntu should work with open-office-online I believe. The main sticking point for FreeBSD is that open-office-online is almost entirely documented around docker images, which FreeBSD can’t use yet.
Their is some interesting rumblings from the docker folks, about abstracting the format to support the linux kernel containers as well as freebsd jails. But thats far flung stuff, im tangenting on.