In this series of three articles, of which this one is the first, we are going to discuss what an IRC network is, how it works and the underlying protocol. IRC gives us a lot more choices and is much more complicated than the regular chat applications, as you will see.
IRC Client Theory - How does IRC work? (Page 2 of 4 )
Internet Relay Chat works by having many servers from all over the world linked together to form an IRC network. There are several of these networks in existence, the main ones being Undernet, DALnet and EFnet. You connect to these servers through a IRC client application.
Once you are connected to the network, you can join a channel and talk to the people in it. Every message that you send will be received by everybody in that channel. Because the servers are generally far apart, a message might take some time to get to the people in the channel.
Each client is distinguished from other clients by a unique (nick)name. In addition to the nickname, servers must have the following information about the client: the real name of the host on which the client is running, the username of the client on that host, and the server to which the client is connected.
The RFC
The RFC document defines the protocol that needs to be followed when creating an IRC client or server. The rules are contained in RFC1459; you can read through it yourself for additional information. Although I will talk about some of the information contained in the RFC, I will not go into much detail about it. So please take the time to read through the document.
Basically IRC is based on the client server model and as such uses the request/response approach. This means commands and replies. Let's go through some of the text that is in the RFC that we will use when we eventually create an Internet Relay Client.
Delphi-Kylix 
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