ownCloud - ownCloud is an open source project enabling businesses to host their own cloud storage while maintaining regulatory and compliance needs.
Sync.com - Sync. com offers a backup tool and a file sharing service, rolled into one.
Resilio Sync - Resilient, fast and scalable file synchronization for enterprises and individuals
Zoho WorkDrive - File storage & content collaboration tool for modern teams
Dropbox - Online Sync and File Sharing
Yandex.Disk - Files on Yandex.Disk won't get lost if your phone or computer breaks.