unison: unison (file-synchronization tool)
unison: 
unison: Unison is a file-synchronization tool for Unix and Windows. It allows
unison: two replicas of a collection of files and directories to be stored on
unison: different hosts (or different disks on the same host), modified
unison: separately, and then brought up to date by propagating the changes in
unison: each replica to the other. Unison shares a number of features with
unison: tools such as configuration management packages (CVS, PRCS,
unison: Subversion, BitKeeper, etc.), distributed filesystems (Coda, etc.),
unison: uni-directional mirroring utilities (rsync, etc.), and other
unison: synchronizers (Intellisync, Reconcile, etc).