Instant messaging actually predates the Internet, first appearing on multi-user operating systems like CTSS and Multics in the mid-1960s. Initially, many of these systems, such as CTSS'.SAVED, were used as notification systems for services like printing, but quickly were used to facilitate communication with other users logged in to the same machine.

As networks developed, the protocols spread with the networks. Some of these used a peer-to-peer protocol (eg talk, ntalk and ytalk), while others required peers to connect to a server. 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.