It offered several channels, each of which could accommodate up to five people, with messages appearing on all users' screens character-by-character as they were typed.
Talkomatic was very popular among PLATO users into the mid-1980s.
The first online chat system was called Talkomatic, created by Doug Brown and David R.
Woolley in 1973 on the PLATO System at the University of Illinois.
Online chat includes web-based applications that allow communication – often directly addressed, but anonymous between users in a multi-user environment.
Web conferencing is a more specific online service, that is often sold as a service, hosted on a web server controlled by the vendor.
Thereby, a feeling similar to a spoken conversation is created, which distinguishes chatting from other text-based online communication forms such as Internet forums and email.
Online chat may address point-to-point communications as well as multicast communications from one sender to many receivers and voice and video chat, or may be a feature of a web conferencing service.
The expression online chat comes from the word chat which means "informal conversation".
The first transatlantic Internet chat took place between Oulu, Finland and Corvallis, Oregon in February 1989.