Which internet chat protocol was created by Jarkko Oikarinen in 1988?

Jarkko Oikarinen created Internet Relay Chat in 1988.

Oikarinen developed IRC while working at the University of Oulu in Finland. The system allowed users to join named channels, exchange messages in real time, and communicate through networked servers. It expanded from a local discussion tool into a worldwide chat network.

IRC helped establish ideas that later appeared in instant messaging and online communities, including channel operators, nicknames, and persistent topic-based rooms. It is not the same as email, which is asynchronous, or Usenet, which is a distributed discussion system based on posted articles rather than live channels.