Dropbox - Online Sync and File Sharing
ownCloud - ownCloud is an open source project enabling businesses to host their own cloud storage while maintaining regulatory and compliance needs.
Mega - Secure File Storage and collaboration
Resilio Sync - Resilient, fast and scalable file synchronization for enterprises and individuals
Google Drive - Access and sync your files anywhere
Syncthing - Syncthing replaces proprietary sync and cloud services with something open, trustworthy and...