Internet Relay Chat

Internet Relay Chat. It is a text-based real-time communication system designed for group discussions in virtual channels, as well as one-to-one conversations via private messages. Developed in 1988 by Finnish student Jarkko Oikarinen at the University of Oulu, it became a foundational technology for online communities. Its architecture, based on a client–server model using the Transmission Control Protocol, enabled global, multi-user conversations that predated the modern World Wide Web.

History

The protocol was created in August 1988 by Jarkko Oikarinen to replace a program called MUT on a Bulletin Board System at the University of Oulu in Finland. Its use expanded rapidly across university networks, particularly within the BITNET and ARPANET research communities. A pivotal moment in its public adoption occurred during the Gulf War in 1991, when real-time updates were relayed from Baghdad as the United States Armed Forces began their offensive. Throughout the 1990s, it became the primary real-time communication layer of the early Internet, hosting communities that would later influence open-source software projects like the Linux kernel and events like the Windows 95 launch.

Technical details

The system operates on a client–server model over the Transmission Control Protocol, typically on port 6667 or nearby ports. The core protocol is defined in RFC 1459, authored by Oikarinen and Darren Reed, with later extensions documented in RFC 2810 through RFC 2813. Communication occurs via plaintext commands, such as those for joining a channel or sending a private message. Servers connect to each other forming an IRC network, with major networks like EFnet and IRCnet routing messages globally. Unlike modern protocols, it originally lacked native support for Transport Layer Security or direct file transfer capabilities, which were later added by various implementations and services like Direct Client-to-Client.

Channels and operation

Users congregate in named channels, which are prefixed with a number sign or an ampersand, and can be moderated by users with special status modes like operator. Channels can be registered with network services such as NickServ and ChanServ, which are provided by software like Atheme or Anope. Key commands govern interaction: `/join` to enter a channel, `/privmsg` to send a message, and `/whois` to query user information. Networks like Undernet and QuakeNet developed complex administrative hierarchies and bot systems to manage large communities, particularly for supporting online gaming clans for titles like Quake and Counter-Strike.

Clients and software

Access requires a client program, with early popular clients including mIRC for Microsoft Windows, BitchX for Unix-like systems, and Irssi for power users. Modern, cross-platform clients like HexChat and WeeChat remain in active development. Server software is dominated by the IRC daemon IRCd, with specific variants like UnrealIRCd and InspIRCd powering major networks. Specialized bot software, such as Eggdrop, was created to automate channel management and games, while bridges to other protocols were built for networks like AOL Instant Messenger and later Slack.

Culture and impact

It fostered a unique cyberculture with its own etiquette, jargon, and ASCII art, influencing early Internet slang like BRB and AFK. It was instrumental in real-time coordination for major events, from the Linux kernel development community to live coverage of the STS-71 Space Shuttle mission. The protocol directly inspired the creation of modern messaging systems like Slack and Discord. Its role in hacker culture was highlighted by groups like L0pht Heavy Industries, and it served as a critical communication tool during emergencies, such as the September 11 attacks and Hurricane Katrina.

Category:Internet protocols Category:Application layer protocols Category:Chat websites Category:Internet culture