GoodSync - GoodSync provides highly reliable file backup and synchronization for both individuals and businesses.

MirrorBackup.net - Mirror Backup protects from data loss by continuously monitoring files and folders, and backing them up to the cloud or a local drive when they change.

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.

UKs Kalender - This program helps you organizing your dates and tasks and reminds you of upcoming events.

Syncthing - Syncthing replaces proprietary sync and cloud services with something open, trustworthy and...

AnyBackup - AnyBackup is designed to keep two pools of volumes in sync with one another.