M.A.R.Go.T. is an acronym for the Metro Authority Rapid Governmental Transit system.
M.A.R.Go.T. (Metro Authority Rapid Governmental Transit System) is a pre-ZAX technology computer system that heads the automated defense system and controls the trains, robots, and other maintenance personnel in the Presidential metro in 2277.
Apparently M.A.R.Go.T. realizes something happened on the surface long ago, but is not sure what. In the end, what happened is meaningless to her anyway as her primary function is to protect the Metro and she will continue to do so until she is no longer able to.
A nearby maintenance terminal in the metro mentions that M.A.R.Go.T. originally had a male voice, but was changed to a female's voice during its development just so that the system could be given the acronym M.A.R.Go.T. as a name. Much to the annoyance of the maintenance worker who was given the responsibility of programming her new voice, this was implied to be somewhat onerous.
Who Dares Wins: M.A.R.Go.T. will ask the player character to approach the console to be identifed. Passing a "very hard" Speech check, using the Science skill, displaying the Senate employee ID, or using the Robotics Expert perk gives access to more information and causes the nearby sentry bots and Mister Gutsies to no longer be hostile. M.A.R.Go.T. will also mention that the fuse for the Metro needs to be replaced before the train to Adams Air Force Base can be used. She will not however, allow the sentry bot with the replacement to be activated until the security breach is contained.
"My primary function is to maintain security for the Presidential Metro System and ensure the safety of all its passengers. I was installed and activated within the Presidential Metro on April 14th, 2065 and switched on at precisely 5:20am. I have been carrying out this primary function since that inception date."
↑"An automated defense system is headed by a Pre-VAX [sic] technology computer system named M.A.R.Go.T. (Metro Authority Rapid Governmental Transit System). She controls the trains, robots, and other maintenance personnel."