Instant messaging (often shortened to IM) is a way of two or more people to communicate over a network. When the sender sends a message, this message is sent to all the recipients in the group.  People use messaging clients to send and receive messages. The type of message supported depends on the specific client, and network. Most of the time, it is text. In some cases, images or other types of media is supported. 

Instant messaging services got many ideas from an older and still popular way to online chat named Internet Relay Chat (IRC). In early instant messaging programs, each letter appeared when it was typed and when letters were deleted to correct typos. These were also seen by the reader. This made it more like a telephone conversation than sending letters. In newer instant messaging programs, the other readers in the conversation generally only sees each line of text right after a new line is started. Most instant messaging programs have a way to set a status message. This works likes the message on a telephone answering machine. It shows whether or not people are online and want to chat.

Benefits 

Instant messaging offers real-time communication and allows easy collaboration, which might be considered more akin to genuine conversation than email's "letter" format. In contrast to e-mail, the parties know whether the peer is available. Most systems allow the user to set an online status or away message so peers are notified when the user is available, busy, or away from the computer. On the other hand, people are not forced to reply immediately to incoming messages. For this reason, some people consider communication via instant messaging to be less intrusive than communication via phone. However, not all popular systems allow the sending of messages to people not currently logged on (offline messages), thus removing much of the difference between IM and email.

Instant messaging allows instantaneous communication between a number of parties simultaneously, by transmitting information quickly and efficiently, featuring immediate receipt of acknowledgment or reply. In certain cases IM involves additional features, which make it even more popular, i.e. to see the other party, e.g. by using ((web-cams)), or to talk directly for free over the internet.

It is possible to save a conversation to read later or look at again. Instant messages typically are may be logged in a local message history which closes the gap to the persistent nature of e-mails and facilitates quick exchange of information like URLs or document snippets (which can be unwieldy when communicated via telephone).

People with an auditory or speech disability 

Instant messaging opens new methods of spontaneous communication for people that have an impairment in hearing, auditory processing, or speech.  It is considered by many a powerful way to allow equal opportunities in communication, without the aid of special devices or services designed for users with hearing loss.

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.

Business application 

Instant messaging has proven to be similar to personal computers, e-mail, and the WWW, in that its adoption for use as a business communications medium was driven primarily by individual employees using consumer software at work, rather than by formal mandate or provisioning by corporate information technology departments. Tens of millions of the consumer IM accounts in use are being used for business purposes by employees of companies and other organizations.

In response to the demand for business-grade IM and the need to ensure security and legal compliance, a new type of instant messaging, called "Enterprise Instant Messaging" ("EIM") was created when Lotus Software launched Lotus Sametime in 1999. Microsoft followed suit shortly thereafter with Microsoft Exchange Instant Messaging, and later created a new platform called Microsoft Office Live Communications Server. Since then, both IBM Lotus and Microsoft have introduced federation between their EIM systems and some of the public IM networks thus employees may use a single interface to both their internal EIM system and their buddies on AOL, MSN, and Yahoo!. Current leading EIM platforms include IBM Lotus Sametime, Microsoft Office Live Communications Server, and Jabber XCP .

The adoption of IM across corporate networks outside of the control of IT organizations creates many risks and liabilities for companies who do not effectively manage and support IM use.  Companies implement specialized IM archiving and security products and services like those from Secure Computing, Akonix, Surfcontrol, and ScanSafe to mitigate these risks and provide safe, secure, productive instant messaging capabilities to their employees.

Risks 

Although instant messaging has many good things, it also has risks and liabilities, especially when used in workplaces. Among these are:

 Security risks (e.g. IM used to infect computers with spyware, viruses, trojans, worms)
 Compliance risks
 Inappropriate use
 Intellectual property leakage

Hackers' use of instant messaging networks to deliver malicious code has grown consistently from 2004 to the present, with the number of discrete attacks listed by the IM Security Center having grown 15% from 347 attacks in 2005 to 406 in 2006. Hackers use two methods of delivering malicious code through IM: delivery of virus, trojan, or spyware within an infected file, and the use of "socially engineered" text with a web address that entices the recipient to click on a URL that connects him or her to a website that then downloads malicious code. Viruses, worms, and trojans typically propagate by sending themselves rapidly through the infected user's buddy list. An effective attack using a "poison URL" may reach tens of thousands of people in minutes when each person's buddy list receives messages appearing to be from a trusted friend. The recipients click on the web address, and the entire cycle starts again. Infections may range from nuisance to criminal, and are becoming more sophisticated each year.

In addition to the malicious code threat, the use of instant messaging at work also creates a risk of non-compliance to laws and regulations governing the use of electronic communications in businesses. In the United States alone there are over 10,000 laws and regulations related to electronic messaging and records retention. The more well-known of these include the Sarbanes-Oxley Act, HIPAA, and SEC 17a-3. Recent changes to Federal Rules of Civil Procedure, effective December 1, 2006, create a new category for electronic records which may be requested during discovery (law) in legal proceedings. Most countries around the world also regulate the use of electronic messaging and electronic records retention in similar fashion to the United States. The most common regulations related to IM at work involve the need to produce archived business communications to satisfy government or judicial requests under law. Many instant messaging communications fall into the category of business communications that must be archived and retrievable.

Organizations of all types must protect themselves from the liability of their employees' inappropriate use of IM. The informal, immediate, and ostensibly anonymous nature of instant messaging makes it a candidate for abuse in the workplace. The topic of inappropriate IM use became front page news in October 2006 when Congressman Mark Foley resigned his seat after admitting sending offensive instant messages of a sexual nature to underage former House pages from his Congressional office PC. The Mark Foley Scandal led to media coverage and mainstream newspaper articles warning of the risks of inappropriate IM use in workplaces. In most countries, corporations have a legal responsibility to ensure harassment-free work environment for employees. The use of corporate-owned computers, networks, and software to harass an individual or spread inappropriate jokes or language creates a liability for not only the offender but also the employer. A survey by IM archiving and security provider Akonix Systems, Inc. in March 2007 showed that 31% of respondents had been harassed over IM at work. Companies now include instant messaging as an integral component of their policies on appropriate use of the World Wide Web, email, and other corporate assets.

Security and archiving 

In the early 2000s, a new class of IT security provider emerged to provide remedies for the risks and liabilities faced by corporations who chose to use IM for business communications. The IM security providers created new products to be installed in corporate networks for the purpose of archiving, content-scanning, and security-scanning IM traffic moving in and out of the corporation. Similar to the e-mail filtering vendors, the IM security providers focus on the risks and liabilities described above.

With rapid adoption of IM in the workplace, demand for IM security products began to grow in the mid-2000s. By 2007, the preferred platform for the purchase of security software had become the "appliance", according to IDC, who estimate that by 2008, 80% of network security products will be delivered via an appliance.

Related pages
 e-mail
 IRC

References

Other websites 

Instant Messenger Security - Best Practices
All About Instant Messengers
List of popular Mobile IM Clients 
Web Messengers Handbook

Instant messaging software
Messaging