Instant messaging: let your fingers do the talking

Instant messaging on the internet is a phenomenon. But it isn't new, and fierce debates continue about the use and abuse of it. Charles Arthur investigates

Millions of people now trade little quips via text while they're online – a sort of textual version of the phone. You type something, and anyone who has your name listed on their Instant Messenger (a protocol with a total of about 100 million users worldwide) list, and logged on, will see that in a box in a corner of their screen.

Is it popular? You bet. The research firm IDC estimates that users sent about 900 million instant messages on a typical day last year, and will send about 7 billion a day by 2004. It is used – a lot – for swapping text. Teenagers use it to have long silent conversations about their love lives. Business executives use it in conference calls to send each other notes without having to say anything aloud. As with all successful products, it has knitted seamlessly into peoples' behaviour.

But what's intriguing is that it has begun to turn into something different from what it was intended for – a quick means of swapping text. It has mutated into a means of swapping files, talking to people, and a pathway for hackers to take control of your computer.

Instant messaging is a phenomenon, though rather like text messaging on mobiles, it isn't new. It appeared in 1984, before the Net, when sites were islands that you dialled into separately. Some bulletin boards implemented a protocol that allowed real-time person-to-person communication – you typed some text, which got sent over your modem and phone line to another user logged onto the same system. AOL added it to its suite of its software in 1989 – America has been online that long. It bubbled along. But it didn't explode.

Things took off in 1996, when AOL brought in the "Buddy List": a collection that you put together of people with IM. Once you're online and signed on, any of your buddies who are online will see that you're there. Buddy Lists are like interactive address books: the names come alight when someone is online and available to chat. You're sure, unlike with e-mail, that they'll see your message.

Teenagers took to AOL's Buddy Lists, and the company still leads the consumer messaging market, particularly after the online service in 1998 bought the Israeli company that developed ICQ ("I Seek You"). Between them, AOL's systems hosted about 33 million IM users in January 2001. Before that, AOL's executives had a debate about whether they should restrict AOL IM to AOL users only – or open it up to anyone for free. Their paying customers loved it; why not persuade non-customers to sign up, with AOL IM as the carrot?

Instead, in 1997, they made it available to anyone. Barry Schuler, chairman of AOL's online service, called it "one of the smartest things we ever did". Last January, there were 33 million IM users and 27 million AOL Online users. The gap is the non-AOL people using IM.

AOL began selling adverts, but other companies wanted in – Microsoft was furious at being shut out of a monopoly. People using Microsoft Messenger (MSM), its rival operating on the MSN service, could not "see" any of the buddies on AOL's lists. In summer 1999, Microsoft's programmers tweaked the MSM program so it could; AOL's programmers tweaked it so it couldn't. Microsoft cried foul, saying AOL was exploiting a monopoly. AOL said it wanted to protect its users from unwanted messages. They then started selling advertising on IM screens.

Instant messaging boomed. Yahoo joined Microsoft in offering a messenger system. AOL's market share has been cut back, to about 50 per cent from 72 per cent in 1999; but the number of users has boomed.

AOL IM is going further. The next innovation was the ability to attach files to messages: like e-mail, but guaranteed. That led to the problem of people being sent viruses, or spreading them unintentionally.

This problem surfaced last week, when w00w00, a security research group, reported that the option to "Play a game with a Buddy" had a loophole that could let a remote user take control of your machine – and wreck it. The flaw only affects the latest Windows versions of the program, and AOL put out a patch last Friday, within a couple of days of the problem being made public.

AOL Instant Messenger, http://www.aim.com: Microsoft Messenger, http://messenger. msn.com/: Yahoo Messenger, http://messenger.yahoo.com/