An early model Xerox Star running a Smalltalk-80 IDE. It pioneered WYSYWIG, came with networking and laser printing, and cast the mould of human-computer interaction for almost every office computer to follow — windows, keyboard and mouse.
A few years ago my friend Jon pulled out the original xerox manuals and said “Look how far we’ve come in thirty years"—Arguing that computers haven’t radically changed since the late 1970’s. At the time, I was stumped—Next time I will pull out my magical touch operated brick and scoff.
Sure enough, languages, systems, and interfaces haven’t radically changed—but the revolutionary change in computers has been the availability.