The programmer, like the poet, works only slightly removed from pure
thought-stuff. He builds his castles in the air, from air, creating by
exertion of the imagination. Few media of creation are so flexible, so
easy to polish and rework, so readily capable of realizing grand
conceptual structures.
Yet the program construct, unlike the poet's words, is real in the
sense that it moves and works, producing visible outputs separate from
the construct itself. It prints results, draws pictures, produces sound,
moves arms. The magic of myth and legend has come true in our time. One
types the correct incantations on a keyboard, and a display screen comes
to life, showing things that never were or could be.
— Frederick P. Brooks, Jr., "The Mythical Man-Month"