Unison runs on both Windows and many flavors of Unix (Solaris, Linux, OS X, etc.) systems. Moreover, Unison works across platforms, allowing you to synchronize a Windows laptop with a Unix server, for example.
designed to manage user specified directories referred to as sync targets from here on out, in tmpfs and to periodically sync them back to the physical disc (HDD/SSD)
"Last week, I told you about my NAS purchase, and my desire to explore desktop applications for backing up your Ubuntu computer. From the administrative interface of my Buffalo NAS, I created a network share that I could access with the different systems in my office. It's an SMB share so that it can also be accessed from Windows if needs arise. I then permanently mount those shares as network file systems (though not NFS) on my Kubuntu Karmic system. This I do from the command line
C. Morbidoni, G. Tummarello, O. Erling, and R. Bachmann-Gmür. Proceedings of the 6th International Semantic Web Conference and 2nd Asian Semantic Web Conference (ISWC/ASWC2007), Busan, South Korea, volume 4825 of LNCS, page 533--546. Berlin, Heidelberg, Springer Verlag, (November 2007)