File Sync Tool for Unix and Windows

Unison seems to be a file-system agnostic replacement for the Robocopy tool found in the NT Resource Kit and others…

“Unison is a file-synchronization tool for Unix and Windows. It allows two replicas of a collection of files and directories to be stored on different hosts (or different disks on the same host), modified separately, and then brought up to date by propagating the changes in each replica to the other.”
(via decafbad)