In August 1991, a Finnish student announced on Usenet that he was developing a free operating system for Intel’s 386 processor. That same month, Tim Berners-Lee released the first code for what he called the World Wide Web, also on Usenet. Twenty years later and both projects have taken over the world: one very visibly – the web – and one almost invisibly: Linux.

The Linux kernel, the low-level core of the free operating system, now drives over 90 percent of the world’s fastest supercomputers, nearly all of the world’s stock exchanges, most of the world’s embedded devices and is switched on in 60 000 to 70 000 new Android mobile phones every day.