Germany
Nextcloud is open-source, self-hosted software that bundles file storage, calendar, contacts, video calls and email into a single platform. Files, Talk and Groupware together make up Nextcloud Hub, and the project is used by EU institutions and Fortune 500 firms alike.
If you control your own infrastructure, Nextcloud is the structural alternative to handing your data to Big Tech, giving you a fully European, self-owned replacement for Dropbox and Google Drive.