GoodSync - GoodSync provides highly reliable file backup and synchronization for both individuals and businesses.
Syncthing - Syncthing replaces proprietary sync and cloud services with something open, trustworthy and...
rsync - rsync is a file transfer program for Unix systems. rsync uses the "rsync algorithm" which provides a very fast method for bringing remote files into sync.
Dropbox - Online Sync and File Sharing
Microsoft OneDrive - Secure access, sharing & file storage
Syncovery - Syncovery will copy your files the way you need it. 30-day trial. Back up your data and synchronize PCs, Macs, servers, notebooks and online storage space. Download for WindowsSyncovery backup software for windows.