January 1, 2013 is seen by some as the internet's 30th birthday. Thirty years ago exactly the US Department of Defence (DoD) commissioned Arpanet, a network that used the Internet protocol suite (IPS) communications system.
Known as 'flag day' it was the first time data 'packet-switching' was used: a new method of linking computers together that paved the way for the arrival of the World Wide Web.
Chris Edwards, an electronics correspondent for Engineering and Technology magazine, said he didn't think those involved in 'flag day' could possibly have predicted the impact of what they were doing.
I don't think that anybody making that switch on the day would have realised the importance of what they were doing. But without it the internet and the World Wide Web as we know them could not have happened.
The internet means there is nowhere and no one in the world you can't reach easily and cheaply.
Based on designs by Welsh scientist Donald Davies, the Arpanet network began as a military project in the late 1960s.
It was developed at American universities and research laboratories, such as the University of California, Los Angeles (UCLA) and the Stanford Research Institute.
Starting in 1973, work on the powerful and flexible IPS and Transmission Control Protocol (TCP) technology which would change mass communications got under way.
The new systems were designed to replace the more vulnerable Network Control Program (NCP) used previously, making sure the network was not exposed to a single point of failure.
This meant a single attack could not bring it down, making it safer and more reliable.
By January 1 1983, the substitution of the older system for the new Internet protocol had been completed and the Internet was born.
English computer scientist Tim Berners-Lee, celebrated in this year's London 2012 Olympic opening ceremony, was then able to use it to host the system of interlinked hypertext documents he invented in 1989, known as the World Wide Web.