Editing Instant messaging (section)

=== Early systems ===
[[File:PLATO-Talkomatic.png|thumb|2014 recreation screenshot of the original Talkomatic program, released in 1973, on the PLATO system (on an orange plasma display)]]
Though the term dates from the 1990s, instant messaging predates the Internet, first appearing on [[multi-user]] [[operating system]]s like [[Compatible Time-Sharing System]] (CTSS) and Multiplexed Information and Computing Service ([[Multics]])<ref>{{cite book |last=Fetter |first=Mirko |date=2019 |title=New Concepts for Presence and Availability in Ubiquitous and Mobile Computing |url=https://books.google.com/books?id=knqIDwAAQBAJ&dq=%22ctss%22+%22write+command%22&pg=PA38 |publisher=[[University of Bamberg]] Press |page=38 |isbn=9783863096236 |quote=The basic concept of sending instantaneously messages to logged in users came with ... CTSS ...}}</ref><ref>{{cite web|author=Tom Van Vleck |url=http://www.multicians.org/thvv/mail-history.html |title=Instant Messaging on CTSS and Multics |publisher=Multicians.org |access-date=2012-05-11}}</ref> in the mid-1960s. Initially, some of these systems were used as notification systems for services like printing, but quickly were used to facilitate communication with other users logged into the same machine. CTSS facilitated communication via text message for up to 30 people.<ref name="gitbooks">{{Cite web|url=https://towcenter.gitbooks.io/guide-to-chat-apps/content/introductionthe_dawn_of/a_brief_history.html|title=A Brief History of Chat Apps · Guide to Chat Apps|website=towcenter.gitbooks.io|access-date=2020-03-23}}</ref>

Parallel to instant messaging were early [[online chat]] facilities, the earliest of which was [[Talkomatic]] (1973) on the [[PLATO (computer system)|PLATO]] system, which allowed 5 people to chat simultaneously on a 512 x 512 plasma display (5 lines of text + 1 status line per person). During the [[bulletin board system]] (BBS) phenomenon that peaked during the 1980s, some systems incorporated chat features which were similar to instant messaging; Freelancin' Roundtable was one prime example. The first<ref>CompuServe Innovator Resigns After 25 Years, The Columbus Dispatch, May 11, 1996, p. 2F</ref> such general-availability commercial online chat service (as opposed to PLATO, which was educational) was the CompuServe [[CB Simulator]] in 1980,<ref>Wired and Inspired, The Columbus Dispatch (Business page), by Mike Pramik, November 12, 2000</ref> created by [[CompuServe]] executive Alexander "Sandy" Trevor in [[Columbus, Ohio]].

As networks developed, the protocols spread with the networks. Some of these used a [[peer-to-peer]] protocol (e.g. [[talk (software)|talk]], ntalk and ytalk), while others required peers to connect to a server (see [[talker]] and [[IRC]]). The [[Zephyr (protocol)|Zephyr Notification Service]] (still in use at some institutions) was invented at MIT's [[Project Athena]] in the 1980s to allow service providers to locate and send messages to users.

[[File:Unix talk screenshot 01.png|thumb|[[Command-line]] Unix "[[talk (software)|talk]]", using a split screen [[user interface]], was popular in the 1980s and early 1990s.]]
Early instant messaging programs were primarily [[real-time text]], where characters appeared as they were typed. This includes the Unix [[talk (software)|"talk"]] command line program, which was popular in the 1980s and early 1990s. Some BBS chat programs (i.e. Celerity BBS) also used a similar interface. Modern implementations of real-time text also exist in instant messengers, such as AOL's Real-Time IM<ref>{{cite web |url=http://help.aol.com/help/microsites/microsite.do?cmd=displayKC&docType=kc&externalId=223568 |title=AOL Instant Messenger's Real-Time IM feature |publisher=Help.aol.com |access-date=2012-05-11 |url-status=dead|archive-url=https://web.archive.org/web/20120312102140/http://help.aol.com/help/microsites/microsite.do?cmd=displayKC&docType=kc&externalId=223568 |archive-date=March 12, 2012 |df=mdy-all }}</ref> as an optional feature.<ref>{{cite web |url=http://www.realjabber.org/real_time_text_demo.html |title=RealJabber.org's animation of real-time text |publisher=Realjabber.org |access-date=2012-05-11 |archive-date=2013-10-26 |archive-url=https://web.archive.org/web/20131026143351/http://realjabber.org/real_time_text_demo.html |url-status=dead }}</ref>

In the latter half of the 1980s and into the early 1990s, the [[Quantum Link]] online service for [[Commodore 64]] computers offered user-to-user messages between concurrently connected customers, which they called "On-Line Messages" (or OLM for short), and later "FlashMail." Quantum Link later became [[America Online]] and made [[AOL Instant Messenger]] (AIM, discussed later). While the Quantum Link client software ran on a [[Commodore 64]], using only the Commodore's [[PETSCII]] text-graphics, the screen was visually divided into sections and OLMs would appear as a yellow bar saying "Message From:" and the name of the sender along with the message across the top of whatever the user was already doing, and presented a list of options for responding.<ref>{{cite web |url=http://www.qlinklives.org/qlink-old/liz1.jpg |title=Screenshot of a Quantum Link OLM |access-date=2012-05-11 |url-status=dead|archive-url=https://web.archive.org/web/20120619055644/http://www.qlinklives.org/qlink-old/liz1.jpg |archive-date=June 19, 2012 |df=mdy-all }}</ref> As such, it could be considered a type of [[graphical user interface]] (GUI), albeit much more primitive than the later [[X Window System|Unix]], [[Microsoft Windows|Windows]] and [[Macintosh]] based GUI IM software. OLMs were what Q-Link called "Plus Services" meaning they charged an extra per-minute fee on top of the monthly Q-Link access costs.

Development of the [[Internet Relay Chat]] (IRC) protocol began in 1989, and this would become the Internet's first widespread instant messaging standard.<ref name="zmescience20181109">{{Cite web |last=Andrei |first=Mihai |date=2018-11-09 |title=The Internet Relay Chat (IRC) turned 30 -- and it probably changed our lives |url=https://www.zmescience.com/science/internet-relay-chat-irc-08112018/ |access-date=2024-08-06 |website=ZME Science |language=en-US}}</ref>