GoodSync automatically synchronizes and backs up all your photos, music, email, and other important files between all your desktops, laptops, servers, and external drives.
Version 11 has been released, see its New Feature List
GoodSync Server can be installed directly on a Western Digital NAS device. It serves files from the device, so they can be accessed by GoodSync on desktop.
GoodSync for Synology NAS is installed directly on the NAS, it serves file from the NAS via GSTP protocol to other GoodSyncs.
GoodSync for QNAP NAS is installed directly on the NAS.
GoodSync for Thecus NAS is installed directly on the NAS.