talk was a program originally used for instant messenger between different users of a single multi-user computer running the Unix operating system. talk eventually accommodated digital conversations between users on different machines as well. Follow-ons to talk included ntalk and ytalk. ytalk was the first to allow conversations between more than two users. All of these programs split the interface into different sections for each participant. The interfaces did not convey the order in which statements typed by different participants would be reassembled into a log of the conversation. Also, all three programs transmitted each character as it was typed, lending a more immediate feel to the discussion than recent instant messenger clients or Internet Relay Chat. Users more familiar with other forms of instant text communication would sometimes find themselves in embarrassing situations by typing something and deciding to withdraw the statement, unaware that the other user(s) had seen it all happen in real time.

A popular program called flash , which sent malformed information via the talk protocol, was frequently used by pranksters to corrupt the terminal output of the unlucky target in the early 1990s. It did this by including terminal commands in the field normally designated for providing the name of the person making the request. When the victim would receive the talk request, the name of the person sending the request would be displayed on their screen. This would cause the terminal commands to execute, rendering the person s display unreadable until they reset it. Later versions of talk blocked flash attempts and alerted the user that one had taken place.

= See also =