Dropbox - Online Sync and File Sharing
GNOME Commander - GNOME Commander is a "two-pane" graphical file manager for the GNOME desktop environment.
Google Drive - Access and sync your files anywhere
xfdesktop - The xfdesktop application manages the desktop backdrop.
ownCloud - ownCloud is an open source project enabling businesses to host their own cloud storage while maintaining regulatory and compliance needs.
CLEX - CLEX is a command-line interface-based file manager for managing and editing project files, no matter where they are stored.