File Sync and Share

DropboxOnline file hosting service offering cloud storage and file synchronisation.
BoxOnline file sharing and content management service focused on business.
SugarSyncCloud file synchronisation service with a focus on backups.
Google DriveFile storage and synchronisation service operated by Google.
B2DropSecure data exchange and cloud storage service focused on research. Currently in beta.
Resilio (formerly Bittorrent Sync)Proprietary peer-to-peer file synchronisation software available on multiple platforms.