bfsync is a file-synchronization tool that allows you to keep a collection of big files synchronized on many machines. It is built around a FuSE filesystem, so repositories can be mounted and the contents can be viewed and modified via the mount point. A collection of commands like commit/push/pull/put/get can be used to control bfsyncs behaviour, and trigger data / history transfers between machines. In addition to synchronizing files between many machines, bfsync can also be used to store back
FreeFileSync allows comparing and synchronizing local file folders. It's performant and without GUI complexity. It detects moved and renamed files, detect conflicts, can operate on locked files, understands symlinks, allows automatic syncing, copyies extended file permissions (NTFS), and it's cross-platform.