Once, supercomputers were mysterious, exotic machines. In the Seventies, Cray and IBM mainframe computers cost millions and were installed in purpose-built offices. They looked like props from 2001: A Space Odyssey, were looked after by uniformed attendants, and were used only by academics and corporate payroll departments.

Today’s supercomputers could not be more different. They’re the grimy industrial powerhouses of the Information Age, impressive only in their enormous scale.

In Chicago, Microsoft is building a data centre around 150 shipping containers stacked like Lego. Each is 40ft long and stuffed with racks of off-the-shelf computers. They run 24 hours a day until their processors burn out. Once a critical mass have failed, the container is unplugged with a forklift truck and a new one installed.

Inside the containers, the machines are just simplified versions of normal home or office PCs, usually running customised free software. Google is building its own network, or “cloud” as the industry terms it, using Velcro to mount components on to cork boards to save money on cases and make assembly faster. It is one thing to build a website that works for 100 people, quite a different challenge to make one that works for 100 million. Cloud computing is how YouTube manages to play tens of millions of videos an hour to users all over the world.

Google’s investment in its cloud has allowed it to develop programs that work just like Microsoft’s profitable Office line (Word, Excel, Powerpoint). Instead of selling the software in boxes for users to install on their own computers, Google’s versions exist only on the web. I am writing this article on Google Docs. It is being stored somewhere on Google’s cloud, and I can access it from any computer in the world. The software is free, it does not need to be installed, and major companies are using cloud-powered software to replace traditional desktop applications.