Unison is a file-synchronization tool for Unix and Windows. See the manual for a detailed look at it's capabilities.
Unison comes in two flavors:
Unison can sync
For syncing desktop machine and neo we use the latter. The recommended way to do this is the remote shell method: We start unison or unison-gtk on the desktop pc. The program will connect to the neo via ssh an start a text-only unison on the neo to retrieve new files or deltas and to modify files on the neo.