Raspberry Pi 4 (with its linux distribution) and an external usb hard drive attached. Install whatever service you want on it. I have Jellyfin and openproject (previously redmine) on it. This mini thingy sits without monitor, keyboard or mouse somewhere next to my router and connected with an ethernet cable. Works flawlessly.

As an 80ies kid: Impossible Mission on my Commodore 64… “Another visitor… Stay a while! Staaay foreveerrr!”

Great initiative! Never heard of it before. Austria should have one more vote now :)

OpenProject has some nice solution for documents: https://www.openproject.org/docs/user-guide/documents/ and https://www.openproject.org/docs/user-guide/file-management/ . Aren’t these enough for you?

Also: OpenProject includes a good wiki for a project. It’s in many cases a better alternative to a document storage, since there is no “download - edit - upload” workflow, so there are no race conditions. (i.e. two people download a doc, edit the doc independently and whoever uploads last “wins” while deleting the previous uploaders changes.)