It is the killer app. The technology that transformed the internet from being a geeky toy to a ubiquitous form of communication that many of us would wonder how we could have lived without. But how many of us know its history, its rich cultural heritage? How can we truly appreciate this tool which we have been given with out an understanding of where it came. To do this let us start with a brief history of the Internet.

In the beginning there was nothing.

And from the nothingness came the ARPAnet. In the glorious year of 1969, while the first moon landings were occurring the ARPAnet was quietly born at Stanford Research Institute (SRI), UCLA, UCSB and the University of Utah.

It was on the 1st October 1969 that the ARPAnet really came into being. On this day Interface Message Processor Number 2 was installed at SRI. The Interface Message Processor, or IMP, was the first ever router. Its role was to interface with a host computer and then transmit packets over the network. The first IMP had been installed at UCLA a month previously, on the Saturday before Labor Day. The IMPs were vital since they allowed two different computers, each using different communications protocols, to talk to each other.

In was on this day that UCLA's Sigma-7 first communicated with SRI's SDS-940 via their IMPs. The start of ARPAnet was in many ways not the best beginning that could be imagined. It is perhaps best put in the words of Leonard Kleinrock, one of the pioneers of these nascent technologies, as well as being a supervisor of the UCLA lab into which IMP-1 was installed.

"So Charley began. He typed in an "L", and over the voice headset, told the SRI programmer he had typed it in and the programmer said "I got the L". Then Charley continued with the "O", got the echo and verbal acknowledgment from the programmer that it had been received. Then Charley typed in the "G", and told him he had now typed in the "G". At this point, the SRI machine crashed!!
Some Beginning!"
(J Seabrook - Deeper, 1997, p.81)

In fact the reason for the crash had nothing to do with the ARPAnet or the two IMPs, but instead was due to a 'feature' of the SDS-940 at SRI. Their computer, upon seeing the "LOG", would try and send back "IN" to complete "LOGIN". Unfortunately the dumb terminal program running on UCLA's Sigma-7 was only programmed to deal with a single character at a time, and so crashed the SDS-940. But this was a highly experimental technology at the time, so these things were to be expected. But they tried again later that day and it all worked as it should.

So it came to be, from this inauspicious start, that the ARPAnet was born. In the beginning ARPAnet was mainly used so that researchers could compile and run software from remote computers, like programmers from SRI used to use the University of Utah's PDP-10 and its compiler as they were preparing to get their own PDP-10. However it was still almost unknown outside this elite inner-sanctum.

We come around now to 1973 where researcher Leonard Klienrock had just returned to LA from a Computing and Communications conference at Sussex University in England. Upon arriving home he discovered that he'd left his electric razor in the UK. At the conference there was an experimental link to ARPAnet so that it could be demonstrated to all the attendees. A satellite link had been used. Packets were traveling from Virginia in the US, over a satellite link to the tracking station at Goonhilly Downs in Cornwall, UK. From there they traveled down a dedicated phone line to the University of London where it was patched to its final destination in Sussex.

When Klienrock arrived home he realized that, since he'd come home a day early, the ARPAnet connection would still be running and there would likely be people still there that would be returning to California. So Klienrock looked on the network to see if anyone was currently online from the conference and discovered that a colleague of his, Larry Roberts, indeed was. So, by using the TALK program, they were able to communicate with each other and Klienrock was able to ask for his razor to be returned to him.

Although there were no 'rules' regarding what could be done on the ARPAnet by those who had authorized access this was still pushing the official parameters for network usage, all be it not for the first time. In Klienrock's own words "It was a thrill. I felt I was stretching the Net." In many ways this was the birth of e-mail. Although it was nothing like e-mail is now it was definitely one of the seeds from which 'modern' e-mail grew.

Now we get to the actual birth of e-mail. The creation of the e-mail system was somewhere between being a lucky accident and a clever hack. Back in the dark ages of the time sharing system, in the era prior to ARPAnet, computer scientists had created a way for users of these systems to exchange messages. This worked by each user having a publicly accessible file that anyone else could append a message to, but only the owner of the file could read from. It was this system that was used in 1972 to the send the first electronic message.

In 1972 there was an engineer by the name of Ray Tomlinson who worked for BBN, the company that designed the IMPs and was responsible for the day-to-day running of the ARPAnet. Tomlinson realized that he could piggy-back messages onto a file transfer protocol that he had written called CPYNET which could then append the message to the mail file of a user on that machine. Using this idea he then wrote two programs, SENDMSG and READMAIL for sending and receiving mail. Thus the doors of e-mail were opened with this technically simple yet revolutionary idea. Tomlinson also created that cultural icon with which we are all now so familiar, the "@" sign. In his own words "I got there first, so I got to choose any punctuation I wanted, I chose the @ sign."

One of the first major proponents of e-mail was Stephen Lukasik, the Director of ARPA from 1971 to 1975. On being appointed one of the first things that he did was to get himself an e-mail address. Lukasik would travel around the country and wherever he was he would use e-mail to stay in touch with his office. In 1973 he commissioned a study that showed the nearly 75% of all ARPAnet traffic was e-mail. The only problem was that, although sending e-mail was easy, reading or replying to e-mail was troublesome due to the lack of decent clients available. Lukasik mentioned this to one of his workers at ARPA, Larry Rodgers - head of the Information Processing Techniques Office, who came back the next day with RD (read) - the first ever mail manager.

These first e-mail applications started a decade of holy-wars - starting in 1973 when an ad-hoc group was started at MIT to try and bring some order and standardization to e-mail. The first rounds of these wars were over what information should be included in mail headers and the use of the @ sign (the @ sign had a special meaning in the Multics operating system - it made the computer ignore everything on that line). In 1975 an electronic forum called the MsgGroup was set up to continue the discussion over the form and direction e-mail should be taking. For the next five years discussions and flames abounded through out the group as to what headers e-mail should have. Part of this discussion were ended in 1977 when RFC733 "STANDARD FOR THE FORMAT OF ARPA NETWORK TEXT MESSAGES" was released, in which the basic structure of an e-mail was laid out. The protocol for the sending and receiving e-mail was finalized in 1982 with the release of RFC821 "SIMPLE MAIL TRANSFER PROTOCOL".

So there we have it. A brief history of e-mail. From a turbulent past to a cultural icon and the killer application of the internet today. How did we ever live with out it?

Katie Hafner, Matthew Lyon - Where Wizards Stay Up Late, The Origins of the Internet; Touchstone, Simon and Schuster, 1998. ISBN 0-684-83267-4
David Hudson - rewired, A Brief (and opinionated) net history; Macmillan Technical Publishing, 1997. ISBN 1-57870-003-5
John Seabrook - Deeper, A two-year odyssey in cyberspace; Faber and Faber, 1997. ISBN 0-571-19207-6
Eric S. Raymond - The New Hackers Dictionary 3rd Ed; MIT Press, 1996. ISBN 0-262-6809200