The Internet is not just a passive, asynchronous medium. Talking in real time with other people online is becoming a popular use of the Internet, and it's usually achieved through an application called Internet Relay Chat or IRC. Internet Relay Chat has had a chequered history, since in its early days, it was the preferred communication medium of hackers, crackers and phreakers. Depending on the server you connect to, it is still dominated largely by hackers, software pirates, sex channels and teenage chat, and because of this, many sites (including Exeter) either don't support it or block it completely.

IRC, like most Internet services, is usually accessed through a client program, which connects to one of a number of interconnected servers, which then relay the messages around the world. When connecting to a server, the user chooses to listen to one or more channels, which usually have a theme or subject. The chat happens in real time, though sometimes there is a delay in the relay, called lag, which is caused by sections of the Internet being congested, or one of the servers being overloaded.

It's also possible to connect to some IRC servers using a web client, though the standard clients are usually more powerful and programmable.

More recently, other similar applications have emerged that achieve a similar function, notably ICQ (I-Seek-You), but including AOL Instant Messenger, MSN Messenger and others. These allow you to define a group of friends, all using the same client, whom you can send messages to, chat to in a group, send files to, etc.. These clients are especially useful as they allow you to see at a glance which of your friends are online. Rather than connecting to a publicly open forum to chat, these allow you to chat easily and (relatively) privately with your friends.