What is Instant Messaging?
Instant messaging is the act of instantly communicating between two or more people 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.
Popular instant messaging services on the public Internet include Qnext, Windows Live Messenger, AOL Instant Messenger, Yahoo! Messenger, Skype, Google Talk, .NET Messenger Service, Jabber, QQ, Excite/Pal iChat and ICQ. These services owe many ideas to an older (and still popular) online chat medium known as Internet Relay Chat (IRC).
Using Instant Messaging for Collaborative Learning: A Case Study by Susana M. Sotillo