If you think this means Content Management System, then you'd better check this: Combat Management Systems powered by Windows for Warships. The Register is running a follow-up story indicating that the UK Defense Secretary is not necessarily found of this U.S. cocktail. Any fear of BSoD while at sea?
"Captain, how do we cast the anchor?
-- Press ctrl-alt-del.
How do we weigh it then?
-- Reboot her."