Wikipedia

IRC

For other uses, seeIRC (disambiguation).

IRC(Internet Relay Chat) is a text-based chat system forinstant messaging.IRC is designed forgroup communicationin discussion forums, calledchannels,[1]but also allows one-on-one communication viaprivate messages[2]as well aschat and data transfer,[3]includingfile sharing.[4]

Internet Relay Chat
Communication protocol
AbbreviationIRC
PurposeInstant messaging
Developer(s)Jarkko Oikarinen
IntroductionAugust 1988;36 years ago(1988-08)
InfluencedIRCv3(standards process working group)
OSI layerApplication layer
Port(s)6667, 6697
RFC(s)RFC1459
The first IRC server, tolsun.oulu.fi, aSun-3server on display near theUniversity of Oulucomputer centre

Internet Relay Chat is implemented as anapplication layerprotocol to facilitate communication in the form of text. The chat process works on aclient–server networking model.Users connect, using a client—which may be aweb app,astandalone desktop program,or embedded into part of a larger program—to an IRC server, which may be part of a larger IRC network. Examples of programs used to connect includeMibbit,IRCCloud,KiwiIRC,andmIRC.

IRC usage has been declining steadily since 2003, losing 60 percent of its users.[5]In April 2011, the top 100 IRC networks served more than 200,000 users at a time.[6]

History

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See also:IRCd § History

IRC was created byJarkko Oikarinenin August 1988 to replace a program called MUT (MultiUser Talk) on aBBScalled OuluBox at theUniversity of OuluinFinland,where he was working at the Department of Information Processing Science. Jarkko intended to extend the BBS software he administered, to allow news in theUsenetstyle, real time discussions and similar BBS features. The first part he implemented was the chat part, which he did with borrowed parts written by his friends Jyrki Kuoppala and Jukka Pihl. The first IRC network was running on a single server named tolsun.oulu.fi.[7]Oikarinen found inspiration in a chat system known asBitnet Relay,which operated on theBITNET.[8]

Jyrki Kuoppala pushed Oikarinen to ask Oulu University to free the IRC code so that it also could be run outside of Oulu, and after they finally got it released, Jyrki Kuoppala immediately installed another server. This was the first "IRC network". Oikarinen got some friends at theHelsinki University of TechnologyandTampere University of Technology[8]to start running IRC servers when his number of users increased and other universities soon followed. At this time Oikarinen realized that the rest of the BBS features probably would not fit in his program.[7]

Oikarinen contacted people at theUniversity of DenverandOregon State University.They had their own IRC network running and wanted to connect to the Finnish network. They had obtained the program from one of Oikarinen's friends, Vijay Subramaniam—the first non-Finnish person to use IRC. IRC then grew larger and got used on the entire Finnish national network—FUNET—and then connected toNordunet,the Scandinavian branch of the Internet. In November 1988, IRC had spread across the Internet and in the middle of 1989, there were some 40 servers worldwide.[7]

EFnet

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In August 1990, the first major disagreement took place in the IRC world. The "A-net" (Anarchy net) included a server named eris.berkeley.edu. It was all open, required no passwords and had no limit on the number of connects. As Greg "wumpus" Lindahl explains:[9]"it had a wildcard server line, so people were hooking up servers andnick-collidingeveryone ". The" Eris Free Network ",EFnet,made the eris machine the first to be Q-lined (Q for quarantine) from IRC. In wumpus' words again:[9]"Eris refused to remove that line, so I formed EFnet. It wasn't much of a fight; I got all the hubs to join, and almost everyone else got carried along." A-net was formed with the eris servers, while EFnet was formed with the non-eris servers. History showed most servers and users went with EFnet. Once A-net disbanded, the name EFnet became meaningless, and once again it was the one and only IRC network.[7]

Around that time IRC was used to report on the1991 Soviet coup d'état attemptthroughout amedia blackout.[10]It was previously used in a similar fashion during theGulf War.[11]Chat logsof these and other events are kept in theibiblioarchive.[12]

Undernet fork

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Another fork effort, the first that made a lasting difference, was initiated by "Wildthang" in the United States in October 1992. (It forked off the EFnet ircd version 2.8.10). It was meant to be just a test network to develop bots on but it quickly grew to a network "for friends and their friends". In Europe and Canada a separate new network was being worked on and in December the French servers connected to the Canadian ones, and by the end of the month, the French and Canadian network was connected to the US one, forming the network that later came to be called "TheUndernet".[7]

The "undernetters" wanted to take ircd further in an attempt to make it use less bandwidth and to try to sort out the channel chaos (netsplitsandtakeovers) that EFnet started to suffer from. For the latter purpose, the Undernet implemented timestamps, new routing and offered the CService—a program that allowed users to register channels and then attempted to protect them from troublemakers. The first server list presented, from 15 February 1993, includes servers from the U.S., Canada, France, Croatia and Japan. On 15 August, the new user count record was set to 57 users.[7]

In May 1993, RFC 1459[13]was published and details a simple protocol for client/server operation, channels, one-to-one and one-to-many conversations.[7]A significant number of extensions like CTCP, colors and formats are not included in the protocol specifications, nor is character encoding,[14]which led various implementations of servers and clients to diverge. Software implementation varied significantly from one network to the other, each network implementing their own policies and standards in their own code bases.

DALnet fork

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During the summer of 1994, the Undernet was itself forked. The new network was calledDALnet(named after its founder: dalvenjah), formed for better user service and more user and channel protections. One of the more significant changes in DALnet was use of longer nicknames (the original ircd limit being 9 letters). DALnet ircd modifications were made by Alexei "Lefler" Kosut. DALnet was thus based on the Undernet ircd server, although the DALnet pioneers were EFnet abandoners. According to James Ng, the initial DALnet people were "ops in #StarTrek sick from the constant splits/lags/takeovers/etc".[7]

DALnet quickly offered global WallOps (IRCop messages that can be seen by users who are +w (/mode NickName +w)), longer nicknames, Q:Lined nicknames (nicknames that cannot be used i.e. ChanServ, IRCop, NickServ, etc.), global K:Lines (ban of one person or an entire domain from a server or the entire network), IRCop only communications: GlobOps, +H mode showing that an IRCop is a "helpop" etc. Much of DALnet's new functions were written in early 1995 by Brian "Morpher" Smith and allow users to own nicknames, control channels, send memos, and more.[7]

IRCnet fork

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In July 1996, after months offlame warsand discussions on the mailing list, there was yet another split due to disagreement in how the development of the ircd should evolve. Most notably, the "European" (most of those servers were in Europe) side that later named itselfIRCnetargued for nick and channel delays whereas the EFnet side argued for timestamps.[7]There were also disagreements about policies: the European side had started to establish a set of rules directing what IRCops could and could not do, a point of view opposed by the US side.[15]

Most (not all) of the IRCnet servers were in Europe, while most of the EFnet servers were in the US. This event is also known as "The Great Split" in many IRC societies. EFnet has since (as of August 1998) grown and passed the number of users it had then. In the (northern) autumn of the year 2000, EFnet had some 50,000 users and IRCnet 70,000.[7]

Modern IRC

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IRC has changed much over its life on the Internet. New server software has added a multitude of new features.

  • Services:Network-operated bots to facilitate registration of nicknames and channels, sending messages for offline users and network operator functions.
  • Extra modes: While the original IRC system used a set of standard user and channel modes, new servers add many new modes for features such as removing color codes from text,[16]or obscuring a user's hostmask ( "cloaking" ) to protect fromdenial-of-service attacks.[17]
  • Proxy detection: Most modern servers support detection of users attempting to connect through an insecure (misconfigured or exploited)proxy server,which can then be denied a connection. This proxy detection software is used by several networks, although that real time list of proxies is defunct since early 2006.[18]
  • Additional commands: New commands can be such things as shorthand commands to issue commands to Services, to network-operator-only commands to manipulate a user's hostmask.[citation needed]
  • Encryption:For the client-to-server leg of the connectionTLSmight be used (messages cease to be secure once they are relayed to other users on standard connections, but it makeseavesdroppingon or wiretapping an individual's IRC sessions difficult). For client-to-client communication,SDCC(Secure DCC) can be used.[citation needed]
  • Connection protocol: IRC can be connected to viaIPv4,the old version of theInternet Protocol,or byIPv6,the current standard of the protocol.

As of 2016,a new standardization effort is under way under a working group called IRCv3, which focuses on more advanced client features such as instant notifications, better history support and improved security.[19]As of 2019,no major IRC networks have fully adopted the proposed standard.[20]

As of June 2021,there are 481 different IRC networks known to be operating,[21]of which the open sourceLibera Chat,founded in May 2021, has the most users, with 20,374 channels on 26 servers; between them, the top 100 IRC networks share over 100 thousand channels operating on about one thousand servers.[22]

After its golden era during the 1990s and early 2000s (240,000 users on QuakeNet in 2004), IRC has seen a significant decline, losing around 60% of users between 2003 and 2012, with users moving tosocial mediaplatforms such asFacebookorTwitter,[5]but also to open platforms such asXMPPwhich was developed in 1999. Certain networks such asFreenodehave not followed the overall trend and have more than quadrupled in size during the same period.[5]However, Freenode, which in 2016 had around 90,000 users, has since declined to about 9,300 users.[23]

The largest IRC networks have traditionally been grouped as the "Big Four"[24][25][26][27]—a designation for networks that top the statistics. The Big Four networks change periodically, but due to the community nature of IRC there are a large number of other networks for users to choose from.

Historically the "Big Four" were:[24][25][26]

IRC reached 6 million simultaneous users in 2001 and 10 million users in 2004–2005, dropping to around 350k in 2021.[citation needed]

The top 100 IRC networks have around 230k users connected at peak hours.[28]

Timeline

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Timeline of major networks:

Technical information

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See also:IRCd
A screenshot ofHexChat,an IRC client forGTKenvironments
Irssi,a text-based IRC client

IRC is an openprotocolthat usesTCP[13]and, optionally,TLS.AnIRC servercan connect to other IRC servers to expand the IRC network.[29]Users access IRC networks by connecting a client to a server.[30]There are many client implementations, such asmIRC,HexChatandirssi,and server implementations, e.g. the originalIRCd.Most IRC servers do not require users to register an account but anicknameis required before being connected.[31]

IRC was originally aplain text protocol[13](although later extended), which on request was assigned port194/TCPbyIANA.[32]However, thede factostandardhas always been to run IRC on 6667/TCP[33]and nearby port numbers (for example TCP ports 6660–6669, 7000)[34]to avoid having to run theIRCdsoftware withroot privileges.

The protocol specified that characters were 8-bit but did not specify the character encoding the text was supposed to use.[14]This can cause problems when users using different clients and/or different platforms want to converse.

All client-to-server IRC protocols in use today are descended from the protocol implemented in the irc2.4.0 version of the IRC2 server, and documented in RFC 1459. Since RFC 1459 was published, the new features in the irc2.10 implementation led to the publication of several revised protocol documents (RFC 2810, RFC 2811, RFC 2812 and RFC 2813); however, these protocol changes have not been widely adopted among other implementations.[citation needed]

Although many specifications on the IRC protocol have been published, there is no official specification, as the protocol remains dynamic. Virtually no clients and very few servers rely strictly on the above RFCs as a reference.[citation needed]

Microsoft made an extension for IRC in 1998 via the proprietaryIRCX.[35]They later stopped distributing software supporting IRCX, instead developing the proprietaryMSNP.

The standard structure of a network of IRC servers is atree.[36]Messages are routed along only necessary branches of the tree but network state is sent to every server[37]and there is generally a high degree of implicit trust between servers. However, this architecture has a number of problems. A misbehaving or malicious server can cause major damage to the network[38]and any changes in structure, whether intentional or a result of conditions on the underlying network, require a net-split and net-join. This results in a lot of network traffic and spurious quit/join messages to users[39]and temporary loss of communication to users on the splitting servers. Adding a server to a large network means a large background bandwidth load on the network and a large memory load on the server. Once established, however, each message to multiple recipients is delivered in a fashion similar tomulticast,meaning each message travels a network link exactly once.[40]This is a strength in comparison to non-multicasting protocols such asSimple Mail Transfer Protocol(SMTP)[citation needed]orExtensible Messaging and Presence Protocol(XMPP)[citation needed].

An IRC daemon can be used on a local area network (LAN). IRC can thus be used to facilitate communication between people within the local area network (internal communication).[41][42]

Commands and replies

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Main article:List of Internet Relay Chat commands

IRC has a line-based structure. Clients send single-line messages to the server,[43]receive replies to those messages[44]and receive copies of some messages sent by other clients. In most clients, users can enter commands by prefixing them with a '/'. Depending on the command, these may either be handled entirely by the client, or (generally for commands the client does not recognize) passed directly to the server, possibly with some modification.[45]

Due to the nature of the protocol, automated systems cannot always correctly pair a sent command with its reply with full reliability and are subject to guessing.[46]

Channels

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The basic means of communicating to a group of users in an established IRC session is through achannel.[47]Channels on a network can be displayed using the IRC commandLIST,[48]which lists all currently available channels that do not have the modes +s or +p set, on that particular network.

Users canjoina channel using theJOINcommand,[49]in most clients available as/join #channelname.Messages sent to the joined channels are then relayed to all other users.[47]

Channels that are available across an entire IRC network are prefixed with a '#', while those local to a server use '&'.[50]Other less common channel types include '+' channels—'modeless' channels without operators[51]—and '!' channels, a form oftimestampedchannel on normally non-timestamped networks.[52]

Modes

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Users and channels may havemodesthat are represented by individual case-sensitive letters[53]and are set using theMODEcommand.[54]User modes and channel modes are separate and can use the same letter to mean different things (e.g. user mode "i" is invisible mode while channel mode "i" is invite only.[55]) Modes are usually set and unset using the mode command that takes a target (user or channel), a set of modes to set (+) or unset (-) and any parameters the modes need.

Some channel modes take parameters and other channel modes apply to a user on a channel or add or remove a mask (e.g. a ban mask) from a list associated with the channel rather than applying to the channel as a whole.[56]Modes that apply to users on a channel have an associated symbol that is used to represent the mode in names replies[57](sent to clients on first joining a channel[49]and use of the names command) and in many clients also used to represent it in the client's displayed list of users in a channel or to display an own indicator for a user's modes.

In order to correctly parse incoming mode messages and track channel state the client must know which mode is of which type and for the modes that apply to a user on a channel which symbol goes with which letter. In early implementations of IRC this had to be hard-coded in the client but there is now a de facto standard extension to the protocol called ISUPPORT that sends this information to the client at connect time using numeric 005.[58][59]

There is a small design fault in IRC regarding modes that apply to users on channels: the names message used to establish initial channel state can only send one such mode per user on the channel,[57]but multiple such modes can be set on a single user. For example, if a user holds both operator status (+o) and voice status (+v) on a channel, a new client will be unable to see the mode with less priority (i.e. voice). Workarounds for this are possible on both the client and server side; a common solution is to use IRCv3 "multi-prefix" extension.[60]

Standard (RFC 1459) modes

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User modes
Letter Symbol Description
i Invisible—cannot be seen without a common channel or knowing the exact name
s Receives server notices
w Receives wallops[61]
o User is an IRC operator (ircop)
Channel modes
Letter Symbol Parameter(s) Description
o @ Name of affected user Channel operator—can change channel modes and kick users out of the channel among other things
s Secret channel—not shown in channel list or user whois except to users already on the channel
p Private channel—listed in channel list as "prv" according to RFC 1459
n Users cannot send messages to the channel externally
m Channel is moderated (only those who hold channel operator or voice status on the channel can send messages to it)
i Only users with invites may enter the channel.
t Only channel operators can change the channel topic.
l Limit number Limits number of users able to be on channel (when full, no new users can join)
b Ban mask (nick!user@host with wildcards allowed) Banshostmasksfrom channel
v + Name of affected user Gives a user voice status on channel (see +m above)
k New channel key Sets a channel key such that only users knowing the key can enter

Many daemons and networks have added extra modes or modified the behavior of modes in the above list.[62][63][64][65]

Channel operators

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Achannel operatoris aclienton anIRC channelthat manages the channel. IRC channel operators can be easily seen by the symbol or icon next to their name (varies by client implementation, commonly a "@" symbol prefix, a green circle, or a Latin letter "+o" / "o" ). On most networks, an operator can:

  • Kick a user.
  • Ban a user.
  • Give another user IRC Channel Operator Status or IRC Channel Voice Status.
  • Change the IRC Channel topic while channel mode +t is set.
  • Change the IRC Channel Mode locks.

Operators

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Main article:IRC operator

There are also users who maintain elevated rights on their local server, or the entire network; these are called IRC operators,[66]sometimes shortened to IRCops or Opers (not to be confused with channel operators). As the implementation of the IRCd varies, so do the privileges of the IRC operator on the given IRCd. RFC 1459[66]claims that IRC operators are "a necessary evil" to keep a clean state of the network, and as such they need to be able to disconnect and reconnect servers. Additionally, to prevent malicious users or even harmful automated programs from entering IRC, IRC operators are usually allowed to disconnect clients and completely ban IP addresses or complete subnets. Networks that carry services (NickServ et al.) usually allow their IRC operators also to handle basic "ownership" matters. Further privileged rights may include overriding channel bans (being able to join channels they would not be allowed to join, if they were not opered), being able to op themselves on channels where they would not be able without being opered, being auto-opped on channels always and so forth.

Hostmasks

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A hostmask is a unique identifier of an IRCclientconnected to an IRCserver.[67][68]IRCservers,services,and other clients, includingbots,can use it to identify a specific IRC session.

The format of a hostmask isnick!user@host.The hostmask looks similar to, but should not be confused with ane-mail address.

The nick part is the nickname chosen by the user and may be changed while connected. The user part is the username reported byidenton the client.[69]If ident is not available on the client, the username specified when the client connected is used after being prefixed with atilde.[70]

The host part is thehostnamethe client is connecting from. If theIP addressof the client cannot be resolved to a validhostnameby the server, it is used instead of the hostname.

Because of theprivacyimplications of exposing the IP address or hostname of a client, someIRC daemonsalso provide privacy features, such as InspIRCd or UnrealIRCd's "+x" mode. Thishashesa client IP address or masks part of a client's hostname, making it unreadable to users other thanIRCops.Users may also have the option of requesting a "virtual host" (or "vhost" ), to be displayed in the hostmask to allow further anonymity. Some IRC networks, such asLibera ChatorFreenode,use these as "cloaks" to indicate that a user is affiliated with a group or project.[71]

URI scheme

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There are three provisional recognizeduniform resource identifier(URI) schemes for Internet Relay Chat:irc,ircs,andirc6.[72]When supported, they allowhyperlinksof various forms, including 

irc://<host>[:<port>]/[<channel>[?<channel_keyword>]]
ircs://<host>[:<port>]/[<channel>[?<channel_keyword>]]
irc6://<host>[:<port>]/[<channel>[?<channel_keyword>]]

(where items enclosed within brackets ([,]) are optional) to be used to (if necessary) connect to the specified host (or network, if known to the IRC client) and join the specified channel.[73](This can be used within the client itself, or from another application such as a Web browser). irc is the default URI, irc6 specifies a connection to be made using IPv6, and ircs specifies a secure connection.

Per the specification, the usualhash symbol(#) will be prepended to channel names that begin with analphanumericcharacter—allowing it to be omitted. Some implementations (for example, mIRC) will do sounconditionallyresulting in a (usually unintended) extra (for example, ##channel), if included in the URL.

Some implementations allow multiple channels to be specified, separated by commas.[74]

Challenges

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Issues in the original design of IRC were the amount of shared state data[75][76]being a limitation on its scalability,[77]the absence of unique user identifications leading to the nickname collision problem,[78]lack of protection fromnetsplitsby means of cyclic routing,[79][80]the trade-off in scalability for the sake of real-time user presence information,[81]protocol weaknesses providing a platform for abuse,[82]no transparent and optimizable message passing,[83]and no encryption.[84]Some of these issues have been addressed inModern IRC.

Attacks

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Because IRC connections may be unencrypted and typically span long time periods, they are an attractive target forDoS/DDoS attackersandhackers.Because of this, careful security policy is necessary to ensure that an IRC network is not susceptible to an attack such as atakeoverwar. IRC networks may alsoK-lineorG-lineusers or servers that have a harming effect.

Some IRC servers supportSSL/TLSconnections for security purposes. This helps stop the use ofpacket snifferprograms to obtain the passwords of IRC users, but has little use beyond this scope due to the public nature of IRC channels. SSL connections require both client and server support (that may require the user to install SSL binaries and IRC client specific patches or modules on their computers). Some networks also use SSL for server-to-server connections, and provide a special channel flag (such as+S) to only allow SSL-connected users on the channel, while disallowing operator identification in clear text, to better utilize the advantages that SSL provides.[85][86]

IRC served as an early laboratory for many kinds of Internet attacks, such as using fakeICMPunreachable messages to breakTCP-based IRC connections (nuking) to annoy users or facilitatetakeovers.

Abuse prevention

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One of the most contentious technical issues surrounding IRC implementations, which survives to this day, is the merit of "Nick/Channel Delay" vs. "Timestamp" protocols. Both methods exist to solve the problem of denial-of-service attacks, but take very different approaches. The problem with the original IRC protocol as implemented was that when two servers split and rejoined, the two sides of the network would simply merge their channels. If a user could join on a "split" server, where a channel that existed on the other side of the network was empty, and gain operator status, they would become a channel operator of the "combined" channel after thenetsplitended; if a user took a nickname that existed on the other side of the network, the server would kill both users when rejoining (a "nick collision" ). This was often abused to "mass-kill" all users on a channel, thus creating "opless" channels where no operators were present to deal with abuse. Apart from causing problems within IRC, this encouraged people to conduct denial-of-service attacks against IRC servers in order to causenetsplits,which they would then abuse.

Thenick delay(ND) andchannel delay(CD) strategies aim to prevent abuse by delaying reconnections and renames. After a user signs off and thenicknamebecomes available, or a channel ceases to exist because all its users parted (as often happens during anetsplit), the server will not allow any user to use that nickname or join that channel, until a certain period of time (thedelay) has passed. The idea behind this is that even if anetsplitoccurs, it is useless to an abuser because they cannot take the nickname or gain operator status on a channel, and thus no collision of a nickname or "merging" of a channel can occur. To some extent, this inconveniences legitimate users, who might be forced to briefly use a different name after rejoining (appending anunderscoreis popular).

The timestamp protocol is an alternative to nick/channel delays which resolves collisions using timestamped priority. Every nickname and channel on the network is assigned a timestamp – the date and time when it was created. When a netsplit occurs, two users on each side are free to use the same nickname or channel, but when the two sides are joined, only one can survive. In the case of nicknames, the newer user, according to their TS, is killed; when a channel collides, the members (users on the channel) are merged, but the channel operators on the "losing" side of the split lose their channel operator status.

TS is a much more complicated protocol than ND/CD, both in design and implementation, and despite having gone through several revisions, some implementations still have problems with "desyncs" (where two servers on the same network disagree about the current state of the network), and allowing too much leniency in what was allowed by the "losing" side. Under the original TS protocols, for example, there was no protection against users setting bans or other modes in the losing channel that would then be merged when the split rejoined, even though the users who had set those modes lost their channel operator status. Some modern TS-based IRC servers have also incorporated some form of ND and/or CD in addition to timestamping in an attempt to further curb abuse.

Most networks today use the timestamping approach. The timestamp versus ND/CD disagreements caused several servers to split away fromEFnetand form the newerIRCnet.After the split, EFnet moved to a TS protocol, while IRCnet used ND/CD.

In recent versions of the IRCnet ircd, as well as ircds using the TS6 protocol (including Charybdis), ND has been extended/replaced by a mechanism called SAVE. This mechanism assigns every client aUIDupon connecting to an IRC server. This ID starts with a number, which is forbidden in nicks (although some ircds, namely IRCnet and InspIRCd, allow clients to switch to their own UID as the nickname).

If two clients with the same nickname join from different sides of a netsplit ( "nick collision" ), the first server to see this collision will forcebothclients to change their nick to their UID, thus saving both clients from being disconnected. On IRCnet, the nickname will also be locked for some time (ND) to prevent both clients from changing back to the original nickname, thus colliding again.

Clients

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Client software

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Further information:Comparison of Internet Relay Chat clients
Scheme of an IRC network withnormal clients(green),bots(blue) andbouncers(orange)

Client software exists for variousoperating systemsor software packages, as well as web-based or inside games. Many different clients are available for the various operating systems, includingWindows,UnixandLinux,macOSand mobile operating systems (such asiOSandAndroid). On Windows,mIRCis one of the most popular clients.[87]SomeLinuxdistributions come with an IRC client preinstalled, such asLinux Mintwhich comes withHexChatpreinstalled.

Some programs which are extensible throughplug-insalso serve as platforms for IRC clients. For instance, a client calledERC,written entirely inEmacs Lisp,is included in v.22.3 of Emacs. Therefore, any platform that can run Emacs can run ERC.

A number ofweb browsershave built-in IRC clients, such as:

  • Operaused to have a client, but no longer supports IRC
  • ChatZillaadd-on for MozillaFirefox(for Firefox 56 and earlier; included as a built-in component ofSeaMonkey).

Web-based clients, such asMibbitand open source KiwiIRC, can run in most browsers.

Games such asWar§ow,[88]Unreal Tournament(up toUnreal Tournament 2004),[89]Uplink,[90]Spring Engine-based games,0 A.D.andZDaemonhave included IRC.[91]

Ustream's chat interface is IRC with custom authentication[92]as well asTwitch's (formerly Justin.tv).[93][94]

Bots

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Main article:IRC bot

A typical use of bots in IRC is to provideIRC servicesor specific functionality within a channel such as to host a chat-based game or provide notifications of external events. However, some IRC bots are used to launch malicious attacks such as denial of service, spamming, or exploitation.[95]

Bouncer

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Main article:BNC (software)

A program that runs as adaemonon aserverand functions as a persistentproxyis known as a BNC or bouncer. The purpose is to maintain a connection to an IRC server, acting as a relay between the server and client, or simply to act as a proxy.[citation needed]Should the client lose network connectivity, the BNC may stay connected and archive all traffic for later delivery, allowing the user to resume their IRC session without disrupting their connection to the server.[96]

Furthermore, as a way of obtaining a bouncer-like effect, an IRC client (typicallytext-based,for exampleIrssi) may be run on an always-on server to which the user connects viassh.This also allows devices that only have ssh functionality, but no actual IRC client installed themselves, to connect to the IRC, and it allows sharing of IRC sessions.[97]

To keep the IRC client from quitting when the ssh connection closes, the client can be run inside aterminal multiplexersuch asGNU Screenortmux,thus staying connected to the IRC network(s) constantly and able to log conversation in channels that the user is interested in, or to maintain a channel's presence on the network. Modelled after this setup, in 2004 an IRC client following theclient–server,calledSmuxi,was launched.[98][99]

Search engines

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There are numerous search engines available to aid the user in finding what they are looking for on IRC.[100][101]Generally the search engine consists of two parts, a "back-end" (or "spider/crawler" ) and a front-end "search engine".

The back-end (spider/webcrawler) is the work horse of the search engine. It is responsible for crawling IRC servers to index the information being sent across them. The information that is indexed usually consists solely of channel text (text that is publicly displayed in public channels). The storage method is usually some sort of relational database, likeMySQLorOracle.[citation needed]

The front-end "search engine" is the user interface to the database. It supplies users with a way to search the database of indexed information to retrieve the data they are looking for. These front-end search engines can also be coded in numerous programming languages.

Most search engines have their own spider that is a single application responsible for crawling IRC and indexing data itself; however, others are "user based" indexers. The latter rely on users to install their "add-on" to their IRC client; the add-on is what sends the database the channel information of whatever channels the user happens to be on.[citation needed]

Many users have implemented their ownad hocsearch engines using the logging features built into many IRC clients. These search engines are usually implemented as bots and dedicated to a particular channel or group of associated channels.

Character encoding

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IRC still lacks a single globally accepted standard convention for how to transmit characters outside the 7-bitASCIIrepertoire. IRC servers normally[clarification needed]transfer messages from a client to another client just as byte sequences, without any interpretation or recoding ofcharacters.The IRC protocol (unlike e.g.MIMEorHTTP) lacks mechanisms for announcing and negotiating character encoding options. This has put the responsibility for choosing the appropriate character codec on the client. In practice, IRC channels have largely used the same character encodings that were also used by operating systems (in particularUnixderivatives) in the respective language communities:

  • 7-bit era:In the early days of IRC, especially amongScandinavianandFinnish languageusers, national variants ofISO 646were the dominantcharacter encodings.These encode non-ASCII characters like Ä Ö Å ä ö å at code positions 0x5B 0x5C 0x5D 0x7B 0x7C 0x7D (US-ASCII:[\]{|}). That is why these codes are always allowed in nicknames. According to RFC 1459, { | } in nicknames should be treated as lowercase equivalents of [ \ ] respectively.[14]By the late 1990s, the use of 7-bit encodings had disappeared in favour ofISO 8859-1,and such equivalence mappings were dropped from some IRC daemons.
  • 8-bit era:Since the early 1990s, 8-bit encodings such asISO 8859-1have become commonly used for European languages. Russian users had a choice ofKOI8-R,ISO 8859-5[citation needed]andCP1251,and since about 2000, modern Russian IRC networks convert between these different commonly used encodings of theCyrillic script.
  • Multi-byte era:For a long time, East Asian IRC channels with logographic scripts in China, Japan, and Korea have been using multi-byte encodings such asEUCorISO-2022-JP.With the common migration from ISO 8859 toUTF-8on Linux and Unix platforms since about 2002, UTF-8 has become an increasingly popular substitute for many of the previously used 8-bit encodings in European channels. Some IRC clients are now capable of reading messages both in ISO 8859-1 or UTF-8 in the same channel, heuristically autodetecting which encoding is used. The shift to UTF-8 began in particular on Finnish-speaking IRC (Merkistö(Finnish)).

Today, the UTF-8 encoding ofUnicode/ISO 10646would be the most likely contender for a single future standard character encoding for all IRC communication, if such standard ever relaxed the 510-byte message size restriction. UTF-8 is ASCII compatible and covers the superset of all other commonly usedcoded character setstandards.

File sharing

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Much like conventionalP2Pfile sharing, users can create file servers that allow them to share files with each other by using customisedIRC botsor scripts for theirIRC client.Often users will group together to distributewarezvia a network of IRC bots.[102]

Technically, IRC provides nofile transfermechanisms itself; file sharing is implemented by IRCclients,typically using theDirect Client-to-Client(DCC) protocol, in which file transfers are negotiated through the exchange of private messages between clients. The vast majority of IRC clients feature support for DCC file transfers, hence the view that file sharing is an integral feature of IRC.[103]The commonplace usage of this protocol, however, sometimes also causes DCC spam. DCC commands have also been used to exploit vulnerable clients into performing an action such as disconnecting from the server or exiting the client.

See also

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Citations

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  1. ^"One-to-many".Internet Relay Chat Protocol.p. 11. sec. 3.2.doi:10.17487/RFC1459.RFC 1459.
  2. ^"One-To-One Communication".Internet Relay Chat: Architecture.p. 5. sec. 5.1.doi:10.17487/RFC2810.RFC 2810.
  3. ^Rollo, Troy."A Description of the DCC Protocol".IRCHelp.org.Retrieved8 April2011.
  4. ^Wang, Wallace (25 October 2004)."Instant Messaging and Online Chat Rooms: Internet Relay Chat (IRC)".Steal this File Sharing Book(1st ed.).San Francisco, California:No Starch Press.pp.61–67.ISBN978-1-59327-050-6.
  5. ^abc"IRC is dead, long live IRC".Pingdom.24 April 2012. Archived fromthe originalon 15 August 2017.Retrieved25 April2016.
  6. ^"IRC Networks – Top 100".irc.netsplit.de.Retrieved26 October2023.
  7. ^abcdefghijkStenberg, Daniel."History of IRC (Internet Relay Chat)".Retrieved25 April2016.I did not experience all of this. I found information on various places and I received information from various people in order to write this. People that have helped me with this include: Greg "wumpus" Lindahl, Vesa "vesa" Ruokonen, James Ng, Tuomas Heino, Richard (eagle`s on undernet), Ari Lemmke
  8. ^abOikarinen, Jarkko."Founding IRC".mIRC.Archivedfrom the original on 27 April 2011.Retrieved8 April2011.
  9. ^ab"History of IRC (Internet Relay Chat)".daniel.haxx.se.Retrieved22 July2023.
  10. ^"IRC transcripts from the time of the 1991 Soviet coup d'état attempt".Chapel Hill, North Carolina:ibiblio.Archived fromthe originalon 28 June 2009.Retrieved8 April2011.
  11. ^"IRC logs of events of the Gulf War".Chapel Hill, North Carolina:ibiblio.Retrieved8 April2011.
  12. ^"Logs of major events in the online community".Chapel Hill, North Carolina:ibiblio.Retrieved8 April2011.
  13. ^abc"Introduction".Internet Relay Chat Protocol.p. 4. sec. 1.doi:10.17487/RFC1459.RFC 1459.
  14. ^abc"Character codes".Internet Relay Chat Protocol.p. 7. sec. 2.2.doi:10.17487/RFC1459.RFC 1459.
  15. ^Engen, Vegard (May 2000)."The Great Split".IRC.org.Retrieved25 April2016.
  16. ^"Channel Modes".UnrealIRCd documentation wiki.Retrieved6 January2018.
  17. ^"Cloaking".UnrealIRCd documentation wiki.Retrieved6 January2018.
  18. ^"Blitzed Open Proxy Monitor Shuts Down".The Open Proxy Monitor which has been provided by the Blitzed IRC network has been shut down…The database was so large that it is near to impossible for the team to backup, or find a new location to continue the service. Added to that, most of the team members do not possess the time anymore to keep the service running.
  19. ^"IRCv3".IRCv3 Working Group. 2016.Retrieved25 April2016.The IRCv3 Working Group is a collection of IRC client and server software authors working to enhance, maintain and standardize the IRC protocol using backwards-compatible extensions.
  20. ^"Networks - IRCv3".2019.Retrieved9 August2019.
  21. ^"IRC Networks - in alphabetical order".netsplit.de.Retrieved12 January2022.
  22. ^"IRC Networks - Top 100".netsplit.de.Retrieved12 January2022.
  23. ^"netsplit.de top 10".Retrieved15 January2021.
  24. ^abCharalabidis, Alex (15 December 1999). "IRCing On The Macintosh: Ircle".The Book of IRC: The Ultimate Guide to Internet Relay Chat(1st ed.).San Francisco, California:No Starch Press. p.61.ISBN978-1-886411-29-6.On large networks such as the Big Four— EFnet, IRCnet, Undernet, and DALnet— trying to list the thousands of channels with Ircle always causes you to disconnect due to the flood of information, while other clients can usually manage the feat, if you are on a direct Ethernet connection.
  25. ^abJones, Steve, ed. (10 December 2002). "Internet Relay Chat".Encyclopedia of New Media: An Essential Reference to Communication and Technology(1st ed.).Thousand Oaks, California:SAGE Publications.p.257.ISBN978-0-7619-2382-4.Today there are hundreds of independent IRC networks, but the "Big Four" are EFNet, UnderNet, Dalnet, and IRCnet.
  26. ^abRittner, Don (3 March 1999).The iMac Book(1st ed.).Scottsdale, Arizona:Coriolis Group. p. 215.ISBN978-1-57610-429-3.There are several large networks: EFnet, UnderNET, DALnet, and IRCnet make up the Big Four.
  27. ^Turban, Efraim; Leidner, Dorothy; McLean, Ephraim; Wetherbe, James (7 February 2005). "Communication".Information Technology for Management: Transforming Organizations in the Digital Economy(5th ed.).Hoboken, New Jersey:John Wiley & Sons.pp.106–107.ISBN978-0-471-70522-2.The largest networks have traditionally been grouped as the "Big Four": EFNet, IrcNet, QuakeNet, and UnderNet.
  28. ^"IRC Networks – Top 100".irc.netsplit.de.netsplit.de.Retrieved15 January2021.
  29. ^"Servers".Internet Relay Chat Protocol.p. 4. sec. 1.1.doi:10.17487/RFC1459.RFC 1459.
  30. ^"Clients".Internet Relay Chat: Architecture.p. 3. sec. 2.2.doi:10.17487/RFC2810.RFC 2810.
  31. ^"Clients".Internet Relay Chat Protocol.p. 5. sec. 1.2.doi:10.17487/RFC1459.RFC 1459.
  32. ^"Port Numbers".Marina del Rey, California:Internet Assigned Numbers Authority.6 April 2011.Retrieved5 April2021.
  33. ^"Connect message".Internet Relay Chat Protocol.p. 29. sec. 4.3.5.doi:10.17487/RFC1459.RFC 1459.
  34. ^Lucas, Mark; Singh, Abhishek; Cantrell, Chris (5 October 2006). "Defining a Firewall". In Henmi, Anne (ed.).Firewall Policies and VPN Configurations.Rockland, Massachusetts:Syngress Publishing. p. 93.ISBN978-1-59749-088-7.
  35. ^Abraham, Dalen (June 1998).Extensions to the Internet Relay Chat Protocol (IRCX).IETF.I-D draft-pfenning-irc-extensions-04.Retrieved8 April2011.
  36. ^"Architecture".Internet Relay Chat: Architecture.pp. 3 – 4. sec. 3.doi:10.17487/RFC2810.RFC 2810.
  37. ^"Introduction".Internet Relay Chat: Architecture.p. 2. sec. 1.doi:10.17487/RFC2810.RFC 2810.
  38. ^"Algorithms".Internet Relay Chat Protocol.p. 64. sec. 9.3.doi:10.17487/RFC1459.RFC 1459.
  39. ^"Network Congestion".Internet Relay Chat: Architecture.pp. 7 – 8. sec. 6.3.doi:10.17487/RFC2810.RFC 2810.
  40. ^"To A Channel".Internet Relay Chat: Architecture.pp. 5 – 6. sec. 5.2.1.doi:10.17487/RFC2810.RFC 2810.
  41. ^"IRC daemons for LAN".Retrieved2 October2014.
  42. ^"Running an own IRC server".Retrieved2 October2014.
  43. ^"Message format in 'pseudo' BNF".Internet Relay Chat Protocol.p. 8. sec. 2.3.1.doi:10.17487/RFC1459.RFC 1459.
  44. ^"Numeric replies".Internet Relay Chat Protocol.p. 10. sec. 2.4.doi:10.17487/RFC1459.RFC 1459.
  45. ^IRC Chat Rooms
  46. ^"IRC List Modes – List mode extension showing pair confusion for lists".25 November 2009.Retrieved8 April2011.
  47. ^ab"To a group (channel)".Internet Relay Chat Protocol.p. 11. sec. 3.2.2.doi:10.17487/RFC1459.RFC 1459.
  48. ^"List message".Internet Relay Chat Protocol.p. 24. sec. 4.2.6.doi:10.17487/RFC1459.RFC 1459.
  49. ^ab"Join message".Internet Relay Chat Protocol.p. 19. sec. 4.2.1.doi:10.17487/RFC1459.RFC 1459.
  50. ^"Channel Scope".Internet Relay Chat: Channel Management.pp. 3 – 4. sec. 2.2.doi:10.17487/RFC2811.RFC 2811.
  51. ^"Channel Properties".Internet Relay Chat: Channel Management.p. 4. sec. 2.3.doi:10.17487/RFC2811.RFC 2811.
  52. ^"Channel lifetime".Internet Relay Chat: Channel Management.p. 5. sec. 3.doi:10.17487/RFC2811.RFC 2811.
  53. ^"Channel Modes".Internet Relay Chat: Channel Management.p. 7. sec. 4.doi:10.17487/RFC2811.RFC 2811.
  54. ^"Mode message".Internet Relay Chat Protocol.p. 21. sec. 4.2.3.doi:10.17487/RFC1459.RFC 1459.
  55. ^"Channel modes".Internet Relay Chat Protocol.pp. 21 – 22. sec. 4.2.3.1.doi:10.17487/RFC1459.RFC 1459.
  56. ^"Channel Access Control".Internet Relay Chat: Channel Management.pp. 10 – 11. sec. 4.3.doi:10.17487/RFC2811.RFC 2811.
  57. ^ab"Command responses: 353 RPL_NAMREPLY".Internet Relay Chat Protocol.p. 51.doi:10.17487/RFC1459.RFC 1459.
  58. ^Roeckx, Kurt (14 October 2004)."The 005 numeric: ISUPPORT".irc.org.Retrieved10 April2011.
  59. ^Brocklesby, Edward (September 2002).IRC RPL_ISUPPORT Numeric Definition.IETF.I-D draft-brocklesby-irc-isupport-03.Retrieved10 April2011.
  60. ^"'multi-prefix' Extension - IRCv3 ".
  61. ^"Operwall message".Internet Relay Chat Protocol.p. 41. sec. 5.6.doi:10.17487/RFC1459.RFC 1459.
  62. ^Butcher, Simon (12 January 2005)."IRC User Modes List".alien.net.au.Retrieved10 April2011.
  63. ^Butcher, Simon (12 January 2005)."IRC Channel Modes List".alien.net.au.Retrieved10 April2011.
  64. ^Butcher, Simon (12 January 2005)."IRC Server Modes List".alien.net.au.Retrieved10 April2011.
  65. ^Olsen, Tommy."IRCd Modes".webtoman.com. Archived fromthe originalon 15 October 2011.Retrieved10 April2011.
  66. ^ab"Operators".Internet Relay Chat Protocol.p. 5. sec. 1.2.1.doi:10.17487/RFC1459.RFC 1459.
  67. ^Döring, Nicola; Schestag, Alexander (23 September 2003)."Soziele Norman in virtuellen Gruppen: ein empirische Analyse am Beispiel ausghewähiter Chat-Channels".In Thiedeke, Udo (ed.).Virtuelle Gruppen: Charakteristika und Problemdimensionen(in German) (2nd ed.).Springer VS[de].pp. 314, 337.ISBN978-3-531-33372-4.Retrieved30 March2010.
  68. ^Rogers, Russ (1 December 2004)."The Mind of Terror".In Devost, Matthew G. (ed.).Hacking a Terror Network: The Silent Threat of Covert Channels(1st ed.).Rockland, Massachusetts:Syngress Publishing. p. 10.ISBN978-1-928994-98-5.Retrieved30 March2010.
  69. ^Petersen, Julie K., ed. (29 May 2002)."Internet Relay Chat".The Telecommunications Illustrated Dictionary(2nd ed.).CRC Press.p. 500.ISBN978-0-8493-1173-4.Retrieved30 March2010.
  70. ^"Frequently-Asked Questions".freenode.Archived fromthe originalon 26 March 2010.Retrieved30 March2010.
  71. ^"IRC/Cloaks".Meta-wiki.Retrieved27 November2011.
  72. ^"Uniform Resource Identifier (URI) Schemes".Internet Assigned Numbers Authority.Retrieved14 October2012.
  73. ^Butcher, Simon (January 2003).Uniform Resource Locator Schemes for Internet Relay Chat Entities.IETF.I-D draft-butcher-irc-url-04.Retrieved10 April2011.
  74. ^"node-irc".npm.26 January 2020.Retrieved30 July2021.
  75. ^"Size".A Discussion on Computer Network Conferencing.pp. 5 – 6. sec. 2.5.1.doi:10.17487/RFC1324.RFC 1324.
  76. ^"Scalability".Internet Relay Chat: Architecture.p. 7. sec. 6.1.doi:10.17487/RFC2810.RFC 2810.
  77. ^Loesch 20031.2.1 Growth
  78. ^"User identification".A Discussion on Computer Network Conferencing.p. 10. sec. 5.4.1.doi:10.17487/RFC1324.RFC 1324.
  79. ^"Trees and cycles".A Discussion on Computer Network Conferencing.p. 10. sec. 5.4.2.doi:10.17487/RFC1324.RFC 1324.
  80. ^Loesch 20031.2.2 Network failures
  81. ^"State Information problems".A Discussion on Computer Network Conferencing.p. 4. sec. 2.1.doi:10.17487/RFC1324.RFC 1324.
  82. ^Loesch 20031.2.3 Sociological and security aspects
  83. ^"Message passing".A Discussion on Computer Network Conferencing.p. 7. sec. 5.2.1.doi:10.17487/RFC1324.RFC 1324.
  84. ^"Conference security".A Discussion on Computer Network Conferencing.p. 8. sec. 5.2.4.doi:10.17487/RFC1324.RFC 1324.
  85. ^"Getting Help on EsperNet".The EsperNet IRC Network.Retrieved31 July2012.
  86. ^brandon (18 May 2010)."New Feature: SSL For Users".DALnet.Retrieved31 July2012.
  87. ^Smith, Roderick W. (8 April 2000)."The Internet: Using IRC to Get Help".The Multi-Boot Configuration Handbook.Handbook Series.Upper Saddle River, New Jersey:Que Publishing.p.289.ISBN978-0-7897-2283-6.Retrieved25 July2010.mIRC is one of the most popular Windows IRC clients.
  88. ^"Warsow Wiki: IRC Module".Archived fromthe originalon 25 April 2011.Retrieved10 April2011.
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  90. ^"The Ultimate Uplink Guide".Retrieved10 April2011.
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  102. ^Vamosi, Robert (8 May 2002)."Pirated movies: Now playing on a server near you".ZDNet.Retrieved10 April2011.
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General bibliography

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Further reading

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Wikidatahas the property:
The WikibookInternet Technologieshas a page on the topic of:IRC
Wikimedia Commons has media related toIRC.
  • IRC Numerics List
  • History of IRC
  • IRC.org– Technical and Historical IRC6 information; Articles on the history of IRC
  • IRChelp.org– Internet Relay Chat (IRC) help archive; Large archive of IRC-related documents
  • IRCv3– Working group of developers, who add new features to the protocol and write specs for them
  • IRC-SourceArchived8 October 2020 at theWayback Machine– Internet Relay Chat (IRC) network and channel search engine with historical data
  • irc.netsplit.de– Internet Relay Chat (IRC) network listing with historical data
Retrieved from "https://en.wikipedia.org/w/index.php?title=IRC&oldid=1265289628"