INTERNET RELAY CHAT

Internet Relay Chat (IRC) is a form of instant communication over the Internet. IRC is a predecessor to the class of applications known as instant messengers, although IRC concentrates more on groups of people talking to each other about a given topic (in what are know as channels, or chat rooms) than on one-on-one communication.

IRC is an Internet protocol that uses TCP. An IRC server can connect to other IRC servers to form an IRC network. Users access IRC networks by connecting a client to a server. The protocol for IRC is open, and there are many client (and server) implementations. Unlike popular instant messaging applications, there is not an inherent login id that one must acquire; it's typically a much more anonymous medium than instant messaging.

IRC was created by Jarkko Oikarinen (WiZ) in August 1988. It was first written to replace a program called MUT (MultiUser Talk) on a BBS called OuluBox in Finland. Jarkko Oikarinen found inspiration in Bitnet Relay Chat which operated on the Bitnet network.

IRC gained prominence when it was used by users behind the Iron Curtain to report on the fall of the USSR during a media blackout. It was later used in a similar fashion by Kuwaitis during the invasion by Saddam Hussein.

IRC is a plaintext protocol, which means that it is fully possible to use IRC via telnet, although quite inconvenient. This makes it less secure than encrypted communications, but SSL can be used to connect to IRC on networks such as P2PChat if the client is compiled with SSL support. Because IRC connections are unencrypted and typically span long time periods, they are an attractive target for hackers. Because of this, careful security policy is necessary to ensure that an IRC network is not susceptible to an attack such as an IRC takeover war. IRC networks also k-line or g-line users or networks that tend to have a harming effect.

RFC 1459 describes the protocol used by the early IRC2; 2810, 2811, 2812 and 2813 describe sets of proposed IRC extensions. Most IRC implementations consist of IRC2 with various add-ons and protocol extensions, resulting in incompatibilities preventing connection of servers running different software.

Today there are many IRC networks; the largest include EFNet, UnderNet, IRCNet, DALnet and QuakeNet. They run various implementations of IRC servers, but the protocol exposed to IRC users is very similar, and all IRC networks can be accessed by the same client software.

Though other forms of instant messaging are generally more popular, IRC still has a loyal following among many computer enthusiasts. The main advantages of IRC over typical instant messaging applications are:

• IRC has an openly specified protocol
• IRC is more suited to the "power user" due to the many options available
• Setting up an IRC server on an Internet server is reasonably straightforward.
• IRC has a large base of users experienced in online etiquette ("netiquette")

Its biggest disadvantage is the lack of a well-defined character encoding for the messages, increasing the difficulty in using non-ASCII character sets.

There are also many programs which are clients, called "bots", short for "robot". The first 'bot was written by Greg Lindahl and provided moderation for the game of Wumpus, but most modern bots either are used to exercise operator privs (controlling channels), to annoy other users (perhaps by spamming them with lots of traffic), or to serve as permanent points of contact for information exchange (an answering machine, file transfer, etc.)

IRC served as an early laboratory for many kinds of Internet attacks, such as using fake ICMP unreachable messages to break TCP-based IRC connections ("nuking") to annoy users or facilitate takeovers.

Because major IRC servers support clients from different parts of the globe that interact in real time, UTC time is generally used for international meetings (i.e., see #bonsai).

Popular IRC clients

• Multiple platforms
  • ChatZilla
  • Gaim
  • jIRC
  • XChat
• Microsoft Windows
  • Bersirc
  • dIRC
  • Klient
  • mIRC
  • pIRCh
  • Trillian
  • vIRC
  • XiRCON
  • Microsoft Comic Chat
• Unix/Linux:
  • BitchX
  • epic
  • IIRC
  • ircII
  • irssi
  • KVIrc
  • Kopete
• MacOS
  • Fire
  • IRCle
  • Snak
• GNUstep
  • TalkSoup
• Amiga
  • AmIRC

See also

• #wikipedia
• Instant messaging
• Peer-to-peer
• IRC client

External links

• IRC networks
• IRC Connection Problems
• SearchIRC: Provides a search for terms in channelname and topic, including many IRC networks
• MyDownloader: Also lists downloadable files off IRC, but down more often