Grsync is a rsync GUI (Graphical User Interface). Rsync is the well-known and powerful command line directory and file synchronization tool. Grsync makes use of the GTK libraries and is released under the GPL license, so it is opensource. It doesn’t need the gnome libraries to run, but can of course run under gnome pretty fine. It can be effectively used to synchronize local directories and it supports remote targets as well (even though it doesn’t support browsing the remote folder). Sample uses of grsync include: synchronize a music collection with removable devices, backup personal files to a networked drive, replication of a partition to another one, mirroring of files, etc.
Storing your rsync backups using grsync into a remote online server may be a very safe and reliable, other than very practical, way to save your data. It allows you to sync multiple computers and to keep your data safe in case of hardware or software failures.