Definition: IAC

(1) For the Indy Autonomous Challenge, see autonomous racing.

(2) (InterApplication Communications) The interprocess communications capability in the Mac starting with System 7.0. IAC events take place behind the scenes and enable one application to send a message to another app. See IPC.

(3) (Internet Access Coalition) An earlier consortium of vendors including Microsoft, Intel and IBM, whose mission in the late 1990s was to keep the Internet affordable and promote high-speed access. They opposed regulations that would enable a telephone company to charge a customer more for a data call than a voice call.