It’s amazing to see the birth of a GUI. Ivan Sutherland’s program named ‘Sketchpad’ is one of most influential programs in the history of graphical user interfaces. Notice how the ‘tools palette’ (in button form) is conveniently placed on the left-hand side of the canvas, where it still rests by default to this day. It’s funny how programs like CAD and Adobe Illustrator have only gotten more complicated over the years, and for most tasks, all we really need is a tablet and an array of buttons. It’s a history lesson for today’s UI designers. Really, there weren’t any real breakthroughs until the introduction of layers in the 1990s.