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  223. Web indexing
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Instant messaging

From Wikipedia, the free encyclopedia

A screenshot of PowWow, one of the first instant messengers with a graphical user interface
A screenshot of PowWow, one of the first instant messengers with a graphical user interface

Instant messaging or IM is a form of real-time communication between two or more people based on typed text. The text is conveyed via computers connected over a network such as the Internet.


Instant messaging requires the use of a client program that hooks up an instant messaging service and differs from e-mail in that conversations are then able to happen in realtime. Most services offer a presence information feature, indicating whether people on one's list of contacts are currently online and available to chat. This may be called a contact list. In early instant messaging programs, each letter appeared as it was typed, and when letters were deleted to correct typos this was also seen in real time. This made it more like a telephone conversation than exchanging letters. In modern instant messaging programs, the other party in the conversation generally only sees each line of text right after a new line is started. Most instant messaging applications also include the ability to set a status message, roughly analogous to the message on a telephone answering machine.

Popular instant messaging services on the public Internet include .NET Messenger Service, AOL Instant Messenger, Excite/Pal, Gadu-Gadu, Google Talk, iChat, ICQ, Jabber, Qnext, QQ, Meetro, Skype, Trillian, Yahoo! Messenger and Rediff Bol Instant Messenger. These services owe many ideas to an older (and still popular) online chat medium known as Internet Relay Chat (IRC).

In early instant messaging programs each character appeared as it was typed. The UNIX "talk" command shown in these screenshots was popular in the 1980s and early 1990s.
In early instant messaging programs each character appeared as it was typed. The UNIX "talk" command shown in these screenshots was popular in the 1980s and early 1990s.


Instant messaging typically boosts communication and allows easy collaboration. In contrast to e-mails, the parties know whether the peer is available. Most systems allow the user to set an online status or away message so peers get notified whenever the user is available, busy, or away from the computer. On the other hand, people are not forced to reply immediately to incoming messages. This way, communication via instant messaging can be less intrusive than communication via phone, which is partly a reason why instant messaging is becoming more and more important in corporate environments. However, not all popular systems allow the sending of messages to people not currently logged on (offline messages), a vital feature when to be used as a less formal e-mail replacement.

It is possible to save a conversation, so as to refer to it later, which is not possible by telephone. Also, the fact that instant messages typically get logged in a local message history closes the gap to the persistent nature of e-mails, facilitating quick, safe, and persistent exchange of information such as URLs or document snippets, which can be unwieldy when done using inappropriate media such as phone. Instant messaging has been known to greatly improve (mostly) children's typing ability, a skill that is becoming increasingly important for the benefit of today's youth.


Instant messaging applications began to appear in the 1970s on multi-user operating systems such as UNIX, initially to facilitate communication with other users logged in to the same machine, then on the local network, and subsequently across the internet. Some of these used a peer-to-peer protocol (eg talk, ntalk and ytalk), while others required peers to connect to a server (see talkers and IRC). Because all of these protocols were based inside a console window, most of those discovering the internet in the mid-1990s and equating it with the web tended not to encounter them.

Modern GUI-based messaging clients began to take off in the late 1990s with ICQ (1996) and AOL Instant Messenger (AIM, 1997) . AOL later acquired Mirabilis, the creators of ICQ. A few years later AOL was awarded two patents for instant messaging by the U.S. patent office. Meanwhile, other companies developed their own applications (Yahoo, MSN, Excite, Ubique, IBM), each with its own proprietary protocol and client; users therefore had to run multiple client applications if they wished to use more than one of these networks.

In 2000, an open source application and open standards-based protocol called Jabber was launched. Jabber servers could act as gateways to other IM protocols, reducing the need to run multiple clients. Modern multi-protocol clients such as Gaim, Trillian and Miranda can use any of the popular IM protocols without the need for a server gateway.

Recently, many instant messaging services have begun to offer video conferencing features, Voice Over IP (VoIP) and web conferencing services. Web conferencing services integrate both video conferencing and instant messaging capabilities. Some newer instant messaging companies are offering desktop sharing, IP radio, and IPTV to the voice and video features.

The term "instant messenger" is a service mark of Time Warner[1] and may not be used in software not affiliated with AOL in the United States. For this reason, the instant messaging client formerly known as GAIM or gAIM is now only to be referred to as Gaim or gaim.


There have been several attempts to create a unified standard for instant messaging: IETF's SIP (Session Initiation Protocol) and SIMPLE (SIP for Instant Messaging and Presence Leveraging Extensions), APEX (Application Exchange), Prim (Presence and Instant Messaging Protocol), the open XML-based XMPP (Extensible Messaging and Presence Protocol), more commonly known as Jabber and OMA's (Open Mobile Alliance) IMPS (Instant Messaging and Presence Service) created specifically for mobile devices.

Most attempts at creating a unified standard for the major IM providers (AOL, Yahoo! and Microsoft) have failed and each continues to use its own proprietary protocol.

However, while discussions at IETF were stalled, Reuters head of collaboration services, David Gurle (the founder of Microsoft's Real Time Communication and Collaboration business), surprised everybody by signing the first inter-service provider connectivity agreement on September 2003. This historic agreement enabled AIM, ICQ and MSN Messenger users to talk with Reuters Messaging counterparts and vice-versa against an access fee. Following this breakthrough agreement between networks Microsoft, Yahoo! and AOL came to a deal where Microsoft's Live Communication Server 2005 (which is interestingly also used by Reuters for its Reuters Messaging service) users would also have the possibility to talk to public instant messaging users. This deal settled once for all the protocol for interconnectivity in the market as SIP/SIMPLE and established a connectivity fee for accessing public instant messaging clouds. Separately, on October 13, 2005 Microsoft and Yahoo! announced that by (the Northern Hemisphere) summer of 2006 they would interoperate using SIP/SIMPLE which is followed on December 2005 by the AOL and Google strategic partnership deal where Google Talk users would be to talk with AIM and ICQ users provided they have an identity at AOL.

There are two ways to combine the many disparate protocols:

  1. One way is to combine the many disparate protocols inside the IM client application. Examples include iChat, Trillian, Gaim, Fire, Proteus, Miranda IM, Adium, Everybuddy, Ayttm, Kopete, Centericq, BitlBee, Windows Messenger, and IMVITE.
  2. The other way is to combine the many disparate protocols inside the IM server application. This approach moves the task of communicating to the other services to the server. Clients need not know or care about other IM protocols. For example, LCS 2005 Public IM Connectivity. This approach is popular in Jabber/XMPP servers however the so-called transport projects suffer the same reverse engineering difficulties as any other project involved with closed protocols or formats.

Some approaches, such as that adopted by the Sonork enterprise IM software or the Jabber/XMPP network or Winpopup LAN Messenger or Softros LAN Messenger, allow organizations to create their own private instant messaging network by enabling them to limit access to the server (often with the IM network entirely behind their firewall) and administer user permissions. Other corporate messaging systems, like the Medianet Innovations MIC, allow registered users to also connect from outside the corporation LAN, by using a secure firewall-friendly HTTPS based protocol. Typically, a dedicated corporate IM server has several advantages such as pre-populated contact lists, integrated authentication, and better security and privacy.

Some networks have made changes to prevent them from being utilized by such multi-network IM clients. For example, Trillian had to release several revisions and patches to allow its users to access the MSN, AOL, and Yahoo! networks, after changes were made to these networks. The major IM providers typically cite the need for formal agreements as well as security concerns as reasons for making these changes.

Mobile Instant Messaging

Mobile Instant Messaging is a presence enabled messaging service that aims to transpose the desktop messaging experience to the usage scenario of being on the move. While several of the core ideas of the desktop experience on one hand apply to a connected mobile device, others do not: Users usually only look at their phone's screen -- presence status changes might occur under different circumstances as happens at the desktop, and several functional limits exist based on the fact that the vast majority of mobile communication devices are chosen by their users to fit into the palm of their hand.

Some of the form factor and mobility related differences need to be taken into account in order to create a really adequate, powerful and yet convenient mobile experience: radio bandwidth, memory size, availability of media formats, keypad based input, screen output, CPU performance and battery power are core issues that desktop device users and even nomadic users with connected notebooks are usually not exposed to.

Several formerly untackled issues have been identified and addressed within IMPS. This standard (IMPS) was developed as part of an early mobile telephone industry initiative to kick off a broader usage of mobile instant messaging . The Open Mobile Alliance has taken over this standard, formerly called Wireless Village, as IMPS V1.0 in November 2002. Since then this standards has been further developed to IMPS V1.3, the latest candidate for release, and is expected to be released before the end of 2006.

A free IMPS-based service exists called Yamigo which allows instant messaging clients pre-installed on many modern wireless phones to connect using standard internet connectivity, even if your carrier doesn't provide his own mobile instant messaging service based on IMPS. Yamigo acts as a standalone mobile instant messaging network, while also holding additional accounts with ICQ, AIM, MSN and Yahoo!, aggregating instant messaging communication from all services into a single user interface. A common misconception is that it can also log-in with Jabber, but it does not do so (yet).

Several large scale mobile telephone industry companies are planning to jointly deliver a ubiquitous, interoperable presence enabled messaging service, built according to interoperability recommendations developed in the GSM Association[2]. Considering these organisations are jointly representing approximately 1.5 billion active Short Text Messaging (SMS) users, it remains to be seen if such an initiative may also help to drive the different industry factions to agree on a truly interoperable approach at least for Mobile Instant Messaging sometime in the not too far future.

In the meantime, other developments by several small companies like MXIT Lifestyle (Pty) Ltd in South Africa have proposed usage of downloadable applications with the intention to create their own approach to IM that runs on most mobile phones worldwide. Essentially, several of these clients are Java applications, such as MXit, that are instantly downloaded and then connected to back-end servers through GPRS/3G Internet Channels. Some of the implementations can connect to other IM services like Jabber, Google Talk, MSN Messenger and AOL's AIM, Rediff Bol Instant Messenger and ICQ, aggregating all IM communication similar to the approach of Yamigo.

Decentralized instant messaging

Some concepts of instant messaging make a decentralized instant messaging system via peer-to-peer technology. In this system like Cspace is one, a distributed hash table lookup is used to determine if buddies are online or not. This instant messaging is effective because it works without a setup of a central server and its failure risk.

Friend-to-friend networks

Instant Messaging may be done in a Friend-to-friend network, in which each node connects to the friends on the friendslist. This allows to communicate to friends of friends and build chatrooms for instant messages with all friends on that network.

User base

  • AIM: 54 million active users (September 2005), 195 million total (January 2003).
  • Windows Live Messenger: 29 million active (Nielsen//NetRatings, August 2005), 155 million total (April 2005).
  • Jabber: 13.5 million enterprise users (Osterman Research August 2005), this does not count users via ISPs and other service providers (estimated to be more than 7.5 million, for a total of at least 21 million)[3].
  • Yahoo! Messenger: 21 million active (September 2005).
  • ICQ: 20 million active world wide[4], 400 million total.
  • Paltalk: 3.3 million unique visitors per month, Media Metrix [5].
  • QQ: 20 million peak online users, 221 million active users [6]
  • Skype: 8 million peak online users (Skype Numerology blog, August 2006), 100 million total (Skype, April 2006).
  • Sametime: 15 million enterprise users.
  • Gadu-Gadu: 5.6 million total (IT & Telecoms in Poland, June 2006).
  • MXit: 2 million (majority in South Africa and more than 150,000 international) (Business Report, 19 October 2006)
  • Ebuddy: 35 million users including 4 million mobile users (eBuddy Press Release, 26 October 2006)
  • Meebo: 0.67 million unique users (Meeblog, 5 October 2006)

See also

  • List of instant messaging protocols
  • Comparison of instant messaging clients
  • List of Jabber server software

Notes and references

  1. ^ Summary of final decisions issued by the trademark trial and appeal board, January 16-20, 2006
  2. ^ Leading Mobile Operators to Deliver Ubiquitous Instant Messaging Industry Press Release at 3GSM World Congress, 12 February 2006
  3. ^ "Google launches IM and voice service", New York Times, 25 August 2005, retrieved 9 June 2006
  4. ^ AOL product description: ICQ, retrieved 9 June 2006
  5. ^ "comScore Media Metrix" August 2006]
  6. ^ "Tencent QQ's Peak Simultaneous Online User Accounts Broke 20 Million", Tencent press release, 3 June 2006, retrieved 14 July 2006

External links

  • Instant messaging at the Open Directory Project
  • Status Messages: A large collection of status messages for Internet Messengers
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