Twenty-five years ago, Apple unveiled the Macintosh computer, a machine that would change the world. The Macintosh transformed the encounter between the computer and its user, making it easier for the ordinary person to understand and control the computing process.

The Macintosh and its success reflected the vision of Mr. Steve Jobs, cofounder of Apple, and the commitment of a team of developers and designers to change the way computing worked. A quarter century later, most computers look like Mac, and Mac does not stand out so much — a sign of its success and the profound impact it has had on the computing world.

Until Jan. 24, 1984, computing was a chore. Indeed, the working assumption for the industry was that most folks did not need such devices. Consistent with that belief, the computing experience was for technicians, not for ordinary people. As a result, the machine and its operating procedures were for "the chosen few." Apple disagreed. Its philosophy was unveiled in striking fashion during the 1984 Super Bowl telecast in a unique commercial. Despite its then historic cost of $1.5 million, it was shown on TV just once more — to announce that "liberation" was on the horizon.