Instant Messenger Services
Instant Messenger Services requires the use of a client program that hooks up to an instant messaging service. IM essentially differs from e-mail in that conversations take place instantaneously. 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 ‘Buddy 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 MSN Messenger Services, AOL Instant Messenger, Yahoo! Messenger, Skype, Google Talk, .NET Messenger Service, Jabber etc. These services owe many ideas to an older online chat medium known as Internet Relay Chat (IRC).
ICQ was the first general instant messenger combining presence or list of contacts with the ability to send messages.. After its introduction, a number of variations of instant messaging have arisen in parallel in many places, each with its own protocol. This has led to users running many instant messaging applications simultaneously to be available on several networks. Alternatively they could use a client which supports many protocols, such as Gaim, Trillian or Miranda clients.On single line bulletin board systems (BBS), the system operator (sysop) and the single caller online could typically chat with one another. One’s typing appeared in real time for the other person as an instant message equivalent.
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.