You may remember a brief frisson when Steve Jobs, Apple's chief executive, announced that the company was switching from IBM processors and would put Intel processors in Apple Macs. Some devotees regarded this as akin to a religious betrayal; more detached folk regarded it as inevitable. IBM had refused to develop the PowerPC processor line any further and it would have been nuts for Apple to go into the chip business. That left only Intel. QED.
Now Apple computers come with Intel's Dual Core processor inside. This columnist is the proud owner of one such machine. For the most part, it is indistinguishable from its predecessor, except that it runs much faster. Naturally, it runs OS X, Apple's operating system. It also runs almost all of the applications created for the earlier processor architecture, so I haven't had to upgrade anything.
So far, so banal; now comes the interesting bit. I downloaded a program called Parallels Desktop. It's an example of 'virtualisation' software. When installed, it popped up a window asking if there were any other operating systems I'd like to run on my machine. I happened to have a disk with the latest distribution of Ubuntu Linux, so I popped it in the drive, and lo! It began to install itself on my hard drive. Parallels had created a 'virtual machine' inside my physical machine. And Linux runs on that virtual machine as if it owned the computer. So I can switch instantly between OS X and Linux.
At this point, dear reader, I know what you're thinking. However fascinating this 'virtual machine' nonsense may be to geeks, it's of no interest to normal human beings. You may feel as Mrs Dave Barry did when her husband, the Miami Herald humorist, took her for a spin in a Humvee and proudly explained that the vehicle could inflate and deflate its tyres while in motion. Why, she asked, would anyone want to do that?
So what's the point of virtualisation? Simply that it provides a vivid illustration of the most disruptive attribute of digital technology - its capability to break the link between an application and a physical platform. Once upon a time, if you bought a PC it ran Windows, and if you bought a Mac it ran Apple's operating system. But now Macs run Windows, and IBM ThinkPads - which have the same processor - can run OS X (though of course Apple is doing its best to head off that possibility). And Linux runs on everything.
This disconnection of application/ service from hardware is happening all over the place. For example, 'radio' used to mean a physical device. Now radio has gone digital and can be received on phones, the web and via digital, satellite and terrestrial television receivers. DAB radios have screens. And TV signals are now being streamed to 3G mobile phones.
Similarly, telephones were once heavy Bakelite devices tethered to the wall. Then they went mobile. Phone calls can now be made by sitting in front of a computer running Skype and just talking out loud. The same thing is happening to computing. A 'computer' was once a giant mainframe machine tended by legions of white-coated attendants. Then it became the 'personal' computer on your desk. To use it you installed programs that turned it into a word processor, spreadsheet calculator, drawing machine or whatever. The 'platform' was the computer.
Then came the net and the web and, later, broadband, enabling the provision of computing services over the network. Why keep your photos on your hard drive when you can store them online? Why run a program on your computer to handle email when you can access your mail anywhere using Hotmail or Gmail? Why buy Microsoft Word when you can do your word-processing online using Writely? The day will come when most people's needs will be met not by buying a computer, but by accessing those services via whatever device they are using at the time. The network is becoming the computer.
And the moral? If your business is platform-specific, diversify. Now.