Maybe not quite on the spot, but a Storage Share (hosted nextcloud) from Hetzner might be an option.
Bonus features and info: You can also share other files, location, calendars, contacts etc. They have a compliant data protection agreement, and are fully GDPR compliant.
Hetzner Storage Share: https://www.hetzner.com/storage/storage-share
Work with informationsecurity and GDPR. And know as a fact that many danish municipalities which administrate the libraries are using, and are happy with, Linux as public facing citizen PC's in libraries.
They use OS2borgerPC, which translates to OS2citizenPC which is maintained and supported by the danish company Magenta. But it's open source, so if you are in another country you could just use it - or better, give Magenta a call. They're great and very reseaonable.
Magenta: https://www.magenta.dk/en/ OS2borgerPC on github: https://github.com/OS2borgerPC
Nice try, Microsoft
Hosted Nextcloud. Hear good things about Hetzner Storage Share.
A Library. Or if digital, Wikipedia and Archive.org.
Firefox and VLC on Windows for years, which just worked. Later XBMC/Kodi and fileserver which where s... on windows but, again, just worked on Linux. When Windows later on kept nagging for something I migrated to 100% Open Source and have been a happy camper ever since!
I'm using Floccus. It has sync to Nextcloud and browser, but seems to work fine offline. Maybe it will work in your usecase.
Conversations or blabber.I'm (fork of the former) are solid. Both on f-droid.
KISS from f-droid.
Maybe not what you're looking for but using Kodi on Pi and laptops as Mediecenter.
Good question, but no ๐
OS2 is a organization which coordinate software development for the participating municipalities and companies which sign up for delivering FOSS. I think OS2 stand for Open Source Software, but not sure.
More about OS2 here: https://www.os2.eu/in-english