The Y Combinator in Ruby (youtube.com)

    Gather 'round while I sing you of Wernher von Braun  
    A man whose allegiance
    Is ruled by expedience
    Call him a Nazi, he won't even frown
    "Nazi, Schmazi!" says Wernher von Braun

    Don't say that he's hypocritical
    Say rather that he's apolitical
    "Once the rockets are up, who cares where they come down?
    That's not my department!" says Wernher von Braun

    Some have harsh words for this man of renown
    But some think our attitude
    Should be one of gratitude
    Like the widows and cripples in old London town
    Who owe their large pensions to Wernher von Braun

    You too may be a big hero
    Once you've learned to count backwards to zero
    "In German, und Englisch, I know how to count down
    Und I'm learning Chinese" says Wernher von Braun

-- Tom Lehrer, That Was The Year That Was, Reprise Records 1965.