Mac OS X Leopard: The Missing Manual

Universal Apps (Intel Macs)

By the end of 2006, Apple had switched its entire Macintosh product line over to Intel's Core Duo processors (the successor to the Pentium).

Yes, that Intel. The company that Mac partisans had derided for years as part of the Dark Side. The company that Steve Jobs routinely belittled in his demonstrations of PowerPC chips (which IBM and Motorola supplied to Apple for more than a decade). The company whose marketing mascot Apple lit on fire in a 1996 attack ad on TV.

Why the change? Apple's computers can only be as fast as the chips inside them, and the chips that IBM had in the works just weren't keeping up with the industry. As one editorial put it, "Apple's doing a U-turn out of a dead-end road."

And sure enough, Intel-based Macs start up and run much faster than the old Macs, thanks to the endless march of speed improvements in the chip-making world. And thanks to that Intel chip, today's Macs can even run Microsoft Windows and all of the thousands of Windows programs. (Chapter 8 has details.)

At the time, though, there was a small glitch: Existing Mac software didn't run on Intel chips.

Apple would have to ask the world's software companies to rewrite their programs yet again, after already having dragged them through the Mac OS 9-to-Mac OS X transition only a few years earlier.

Fortunately, the transition wasn't as gruesome as you might expect. First, Apple had already secretly recompiled (reworked) Mac OS X itself to run on Intel chips, beginning with ...