Source : Free On-Line Dictionary of Computing

waldo
     
        /wol'doh/ [Robert A. Heinlein's story "Waldo"] 1. A mechanical
        agent, such as a gripper arm, controlled by a human limb.
        When these were developed for the nuclear industry in the
        mid-1940s they were named after the invention described by
        Heinlein in the story, which he wrote in 1942.  Now known by
        the more generic term "telefactoring", this technology is of
        intense interest to NASA for tasks like space station
        maintenance.
     
        2. At Harvard (particularly by Tom Cheatham and students),
        this is used instead of {foobar} as a metasyntactic variable
        and general nonsense word.  See {foo}, {bar}, {foobar},
        {quux}.
     
        [{Jargon File}]