It has often been said that change is the only constant in the 21st Century. And there is little doubt that the restless tone of these times is something that the web has helped to accelerate, but the only reason that [...] the web can cope with that punishing pace is thanks to work done four decades ago by British mathematician Donald Davies at the UK's National Physica Laboratory (NPL). On 5 August 1968 Dr Davies gave the first public presentation of work he had been doing on a method of moving data around computer networks called "packet switching".