In Opinion Journal, Om Malick explores the importance of software platforms:

A couple of years ago, in the days before YouTube, a short video clip spread like wildfire on the Internet. It showed the fourth richest man on the planet, Steve Ballmer, the chief executive of Microsoft, doing a crazy jig onstage at a conference, screaming "developers, developers, developers." Truer words have never been spoken--or repeated. Without "developers," Microsoft would not possess its desktop monopoly or billions of dollars in profits.

Those developers are the little platoons of software programmers and product-inventors who turn operating systems (like Microsoft's Windows), Internet browsers (Firefox), game devices (PlayStation) and much else into something more than themselves--into "platforms" upon which a whole economic ecosystem rests. It is impossible to imagine Dell Computer's success, or that of Intuit Corp. or even Electronic Arts (the videogame company) without the platform that Windows constructed with the help, so to speak, of Microsoft. Windows is but one example of many software engines that have propelled mega-billion-dollar industries and created wealth beyond compare. Just as the internal combustion engine led to the formation of the modern automobile industry and ended up driving so much else in the economy (think only of steel and gasoline), invisible engines are now powering the vast postindustrial economies in which we live and work.

Such is the persuasive thesis of "Invisible Engines," by David S. Evans, Andrei Hagiu and Richard Schmalensee. The authors document the rise of platforms, outline the strategies by which they are developed and marketed, and offer little-known details about popular devices--Sony's PlayStation, Apple's iPod, Palm Treo--that have become essential aspects of our modern lives.