(Seriously: We use desktop versions of Office apps based on Office 365 but I have not discovered any collaboration features so far. Where are they hidden? Are they compliant with European data privacy and labor law?)
I don't know enough about the admin side, but perhaps it's something that needs to be enabled separately. From a user perspective it 'just works' in our office:
If several people open a document shared on OneDrive, that document is opened in a collaboration mode where you can see others working on it, similar to Google Drive.
A menu appears at the bottom of the screen[1] showing who's editing that file. If you have Lync/Skype for Business, clicking on those names opens an IM to that person.
Re privacy, a quick search shows their cloud services are compliant with ISO 27018 as of February this year[2]
(Seriously: We use desktop versions of Office apps based on Office 365 but I have not discovered any collaboration features so far. Where are they hidden? Are they compliant with European data privacy and labor law?)