This article provides a concise, clearly written discussion of the history of the well-known Aloha protocol by Prof. Norman Abramson, the key individual responsible for its invention, development, and initial deployments in a variety of applications involving joint use of a given medium by potentially interfering systems. He discusses the use of this protocol and its various incarnations, continuing to this day, in such disparate applications as wired Ethernet, satellite communications, and mobile wireless systems, among others. What is so amazing about this scheme is its basic simplicity, yet profound ability to find application in such a widespread range of communication systems. The protocol, in its most concise form, says transmit at will. If interference is detected, retransmit some random time later. What can be simpler? Yet, despite its apparent simplicity, such a protocol was not at all obvious at the time of its invention and initial deployment.