IRC stands for 'Internet Relay Chat' and was developed in 1988 by Jarkko Oikarinen. Oikarinen designed IRC while he worked in the Department of Information Processing Science at the University of Oulu (Finland). Oikarinen was assisted in publishing the specification for IRC by Darren Reed (Request for Comments: 1459). Oikarinen claims that the inspiration for IRC came from existing instant chat programs like MultiUser Talk (MUT) and Bitnet Relay Chat. IRC was originally designed specifically to work on the TCP/IP network protocol (Internet); Oikarinen stated that in the future IRC need not use TCP/IP as the "only sphere in which it operates". To expand the popularity of IRC, Oikarinen contacted academic peers at a range of international universities to adopt and popularise the technology, which included: Vijay Subramaniam, Jeff Trim, David Bleckmann and Todd Ferguson.
- Jarkko Oikarinen, inventor of Internet Relay Chat
IRC is defined as an 'open protocol', and is part of the application layer of the Internet protocol suite (TCP/IP). Just as with other application layer protocols, the IRC protocol uses and works alongside the the Transmission Control Protocol (TCP) of the Internet protocol suite; TCP guarantees the transportation of IRC data in a reliable manner. IANA assigned the TCP port number 194 to IRC. The protocol of IRC was standardised in the following Request For Comment documents: RFC 1459, 2810, 2811, 2812 and 2813. IRC can be classed as: 1) Multi-user, multi-channel chat system; 2) Once setup, chatting on IRC is totally free. The IRC protocol is described as 'dynamic', with no official protocol standard that all IRC servers and client programs adopt.
IRC is based on a client-server model: with users running a client programs, such as MIRC, that connect the user to a server connected to the Internet. The server links to other servers to form a IRC network: the IRC network structure is described as a 'tree network', or 'star bus network'. This network structure allows messages from one user (client) to be transported to another, which means that people from all over the world can talk to each other "live" and simultaneously. The IRC network structure relies on trust between servers, and the network stability can suffer from malfunctioning or misbehaving server. IRC client programs use line-based user commands that use a slash and angle bracket syntax.
While IRC usage has decreased with the advent of voice/video communication - like with Skype - there are still hundreds of thousands of IRC users and channels. There are a number of popular IRC client programs, such as: Mirc, Pirch, Virc, Ircle and MacIrc. Connecting and using IRC is simple, all a user requires to begin using IRC: Connection to the Internet; IRC client program such as: mIRC for the Windows operating system; ircII for the UNIX operating system; and Ircle for the Macintosh platform.